2-cyanophenyl fused heterocyclic  compounds, and compostions and uses thereof

ABSTRACT

Fused heterocyclic compounds are provided according to formula 1: 
     
       
         
         
             
             
         
       
     
     where R 1 , R 2 , R 3 , and m are as defined herein. Provided compounds and pharmaceutical compositions thereof are useful for the prevention and treatment of a variety of conditions in mammals including humans, including by way of non-limiting example, pain, inflammation, cognitive disorders, anxiety, depression, and others.

RELATED APPLICATIONS

The present application claims the priority of co-pending provisionalapplications U.S. Ser. No. 60/925,109, filed on Apr. 17, 2007 and U.S.Ser. No. 61/010,512, filed on Jan. 8, 2008. The disclosures of all ofthe aforementioned applications are incorporated by reference herein intheir entireties. Applicants claim the benefits of these applicationsunder 35 U.S.C. §119(e).

FIELD

Provided herein are fused heterocyclic compounds of the classtetrahydropyrido[4,3-d]pyrimidines and pharmaceutical compositionscomprising such compounds. Also provided are methods for preventingand/or treating conditions in mammals, such as (but not limited to)arthritis, Parkinson's disease, Alzheimer's disease, asthma, myocardialinfarction, pain syndromes (acute and chronic or neuropathic),neurodegenerative disorders, schizophrenia, cognitive disorders,anxiety, depression, inflammatory bowel disease and autoimmunedisorders, and promoting neuroprotection, using the fused heterocycliccompounds and pharmaceutical compositions provided herein.

BACKGROUND

Therapeutic strategies for the effective management of pain and centralnervous system disorders or diseases are sought.

International Patent Application, Publication Number WO 02/08221discloses diaryl piperazine and related compounds which are said to beuseful in the treatment of chronic and acute pain conditions, itch andurinary incontinence.

WO02/053558 describes certain quinazolone derivatives as alpha 1A/Badrenergic receptor antagonists, and WO03/076427 and WO04/041259 bothdescribe compounds of the same class for use in the treatment of femalesexual dysfunction. WO04/56774 describe certain substitutedbiphenyl-4-carboxylic acid arylamide analogues having possibleapplication as receptor modulators. Also, WO03/104230 describes certainbicyclic pyrimidine derivatives, and US Published Application Serial No.20030092908 and WO02/087513 describe fused heterocyclic PDE7 inhibitors.

U.S. Pat. Nos. 3,424,760 and 3,424,761 both describe a series of3-ureidopyrrolidines that are said to exhibit analgesic, central nervoussystem, and pyschopharmacologic activities. These patents specificallydisclose the compounds 1-(1-phenyl-3-pyrrolidinyl)-3-phenyl urea and1-(1-phenyl-3-pyrrolidinyl)-3-(4-methoxyphenyl)urea respectively.International Patent Applications, Publication Numbers WO 01/62737 andWO 00/69849 disclose a series of pyrazole derivatives which are statedto be useful in the treatment of disorders and diseases associated withthe NPY receptor subtype Y5, such as obesity. WO 01/62737 specificallydiscloses the compound5-amino-N-isoquinolin-5-yl-1-[3-(trifluoromethyl)phenyl]-1H-pyrazole-3-carboxamide.WO 00/69849 specifically discloses the compounds5-methyl-N-quinolin-8-yl-1-[3-(trifluoromethyl)phenyl]-1H-pyrazole-3-carboxamide,5-methyl-N-quinolin-7-yl-1-[3-trifluoromethyl)phenyl]-1H-pyrazole-3-carboxamide,5-methyl-N-quinolin-3-yl-1-[3-(trifluoromethyl)phenyl]-1H-pyrazole-3-carboxamide,N-isoquinolin-5-yl-5-methyl-1-[3-(trifluoromethyl)phenyl]-1H-pyrazole-3-carboxamide,5-methyl-N-quinolin-5-yl-1-[3-(trifluoromethyl)phenyl]-1H-pyrazole-3-carboxamide,1-(3-chlorophenyl)-N-isoquinolin-5-yl-5-methyl-1H-pyrazole-3-carboxamide,N-isoquinolin-5-yl-1-(3-methoxyphenyl)-5-methyl-1H-pyrazole-3-carboxamide,1-(3-fluorophenyl)-N-isoquinolin-5-yl-5-methyl-1H-pyrazole-3-carboxamide,1-(2-chloro-5-trifluoromethylphenyl)-N-isoquinolin-5-yl-5-methyl-1N-pyrazole-3-carboxamide,5-methyl-N-(3-methylisoquinolin-5-yl)-1-[3-(trifluoromethyl)phenyl]-1N-pyrazole-3-carboxamide,5-methyl-N-(1,2,3,4-tetrahydroisoquinolin-5-yl)-1-[3-(trifluoromethyl)phenyl]-1H-pyrazole-3-carboxamide.

German Patent Application Number 2502588 describes a series ofpiperazine derivatives. This application specifically discloses thecompoundN-[3-[2-(diethylamino)ethyl]-1,2-dihydro-4-methyl-2-oxo-7-quinolinyl]-4-phenyl-1-piperazinecarboxamide.

SUMMARY

Fused heterocylic compounds, and pharmaceutical compositions thereof,having potency and selectivity in the prevention and treatment ofconditions that have been associated with neurological and inflammatorydisorders and dysfunctions are provided herein.

In particular, compounds, pharmaceutical compositions and methodsprovided are useful to treat, prevent or ameliorate a range ofconditions in mammals such as, but not limited to, pain of variousgenesis or etiology, for example acute, chronic, inflammatory andneuropathic pain, dental pain and headache (such as migraine, clusterheadache and tension headache). In some embodiments, compounds,pharmaceutical compositions and methods provided are useful for thetreatment of inflammatory pain and associated hyperalgesia andallodynia. In some embodiments, compounds, pharmaceutical compositionsand methods provided are useful for the treatment of neuropathic painand associated hyperalgesis and allodynia (e.g. trigeminal or herpeticneuralgia, diabetic neuropathy, causalgia, sympathetically maintainedpain and deafferentation syndromes such as brachial plexus avulsion). Insome embodiments, compounds, pharmaceutical compositions and methodsprovided are useful as anti-inflammatory agents for the treatment ofarthritis, and as agents to treat Parkinson's Disease, Alzheimer'sDisease, asthma, myocardial infarction, neurodegenerative disorders,inflammatory bowel disease and autoimmune disorders, renal disorders,obesity, eating disorders, cancer, schizophrenia, epilepsy, sleepingdisorders, cognitive disorders, depression, anxiety, blood pressure, andlipid disorders.

Accordingly, in one aspect, fused heterocyclic compounds are providedthat have formula 1:

wherein

-   -   R¹ is cycloalkyl, cycloheteroalkyl, aryl or heteroaryl        unsubstituted or substituted with one or more R⁴ groups;    -   R² is H, substituted or unsubstituted C₁-C₆ alkyl or cycloalkyl;    -   each R³ and R⁴ is independently selected from the group        consisting of H, alkyl, acyl, acylamino, alkylamino, alkythio,        alkoxy, alkoxycarbonyl, alkylarylamino, arylalkyloxy,        arylalkyloxy, amino, aryl, arylalkyl, sulfo, substituted sulfo,        substituted sulfonyl, substituted sulfinyl, substituted        sulfanyl, azido, carbamoyl, carboxyl, cyano, cycloalkyl,        cycloheteroalkyl, dialkylamino, halo, heteroaryloxy, heteroaryl,        heteroalkyl, hydroxy, nitro, and thiol; m is 1, 2, 3 or 4;

or a pharmaceutically acceptable salt, solvate, prodrug, tautomer orisotopic variant thereof.

In another aspect, fused heterocyclic compounds are provided that haveformula 2:

wherein R¹, R², R³, and R⁴ are as described for formula 1 or apharmaceutically acceptable salt, solvate, prodrug, tautomer or isotopicvariant thereof.

In certain embodiments, with respect to formula 2, R³ is halo,substituted or unsubstituted C₁-C₆ alkyl or cycloalkyl. In furtherembodiments, R³ is Cl, F, Me or CF₃.

In certain embodiments, the compounds according to formulae 1-2 areenantiomerically pure. In certain embodiments, provided arepharmaceutical compositions comprising enantiomerically pure compoundsaccording to formulae 1-2. In certain embodiments, provided are methodsof treatment that comprise administering an enantiomerically purecompound according to formulae 1-2 or a pharmaceutical compositioncomprising an enantiomerically pure compound according to formulae 1-2.

Accordingly, in one aspect, fused heterocyclic compounds are providedthat have formula 3a or 3b:

wherein R¹, R² and R⁴ are as described for formula 1; and R³ is halo,substituted or unsubstituted C₁-C₆ alkyl or cycloalkyl; or apharmaceutically acceptable salt, solvate, prodrug, tautomer or isotopicvariant thereof.

In certain embodiments, the compounds according to formula 3a or 3b areenantiomerically pure. In certain embodiments, pharmaceuticalcompositions are provided comprising enantiomerically pure compoundsaccording to formula 3a or 3b. In certain embodiments, provided aremethods of treatment that comprise administering an enantiomericallypure compound according to formula 3a or 3b or a pharmaceuticalcomposition comprising an enantiomerically pure compound according toformula 3a or 3b.

In another aspect, pharmaceutical compositions are provided comprising afused heterocyclic compound provided herein, and a pharmaceuticalcarrier, excipient or diluent. The pharmaceutical composition cancomprise one or more of the fused heterocyclic compounds describedherein.

It will be understood that fused heterocyclic compounds provided hereinuseful in the pharmaceutical compositions and treatment methodsdisclosed herein, can be pharmaceutically acceptable as prepared andused.

In another aspect, methods are provided for preventing, treating orameliorating a condition from among those listed herein, andparticularly, such condition as may be associated with, e.g., arthritis,asthma, myocardial infarction, lipid disorders, cognitive disorders,anxiety, schizophrenia, depression, memory dysfunctions such asAlzheimers disease, inflammatory bowel disease and autoimmune disorders,which method comprises administering to a mammal in need thereof anamount of one or more of the compounds as provided herein, orpharmaceutical composition thereof, effective to prevent, treat orameliorate the condition.

In yet another aspect, methods are provided for preventing, treating orameliorating a condition that gives rise to pain responses or thatrelates to imbalances in the maintenance of basal activity of sensorynerves in a mammal. The fused heterocyclic compounds provided hereinhave use as analgesics for the treatment of pain of various geneses oretiology, for example acute, inflammatory pain (such as pain associatedwith osteoarthritis and rheumatoid arthritis); various neuropathic painsyndromes (such as post-herpetic neuralgia, trigeminal neuralgia, reflexsympathetic dystrophy, diabetic neuropathy, Guillian Barre syndrome,fibromyalgia, phantom limb pain, post-masectomy pain, peripheralneuropathy, HIV neuropathy, and chemotherapy-induced and otheriatrogenic neuropathies); visceral pain, (such as that associated withgastroesophageal reflex disease, irritable bowel syndrome, inflammatorybowel disease, pancreatitis, and various gynecological and urologicaldisorders), dental pain and headache (such as migraine, cluster headacheand tension headache).

In one aspect, methods are provided for preventing, treating orameliorating a neurodegenerative disease or disorder in a mammal. Aneurodegenerative disease or disorder can, for example, be Parkinson'sdisease, Alzheimer's disease and multiple sclerosis; diseases anddisorders which are mediated by or result in neuroinflammation such as,for example, encephalitis; centrally-mediated neuropsychiatric diseasesand disorders such as, for example, depression mania, bipolar disease,anxiety, schizophrenia, eating disorders, sleep disorders and cognitiondisorders; epilepsy and seizure disorders; prostate, bladder and boweldysfunction such as, for example urinary incontinence, urinaryhesitancy, rectal hypersensitivity, fecal incontinence, benign prostatichypertrophy and inflammatory bowel disease; respiratory and airwaydisease and disorders such as, for example, allergic rhinitis, asthmaand reactive airway disease and chronic obstructive pulmonary disease;diseases and disorders which are mediated by or result in inflammationsuch as, for example rheumatoid arthritis and osteoarthritis, myocardialinfarction, various autoimmune diseases and disorders; itch/pruritussuch as, for example, psoriasis; obesity; lipid disorders; cancer; andrenal disorders. Typically, the methods comprise administering aneffective condition-treating or condition-preventing amount of one ormore of the compounds as provided herein, or pharmaceutical compositionthereof, to the mammal in need thereof.

In addition to the methods of treatment set forth above, the presentinvention extends to the use of any of the compounds of the inventionfor the preparation of medicaments that may be administered for suchtreatments, as well as to such compounds for the treatments disclosedand specified.

In additional aspects, methods are provided for synthesizing the fusedheterocyclic compounds described herein, with representative syntheticprotocols and pathways described below. In certain embodiments, providedare methods of making enantiomerically pure compounds according toformula 1 by asymmetric synthesis. In certain embodiments, provided aremethods of making enantiomerically pure compounds according to formula 1by chiral resolution.

Other objects and advantages will become apparent to those skilled inthe art from a consideration of the ensuing detailed description.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

The following terms are intended to have the meanings presentedtherewith below and are useful in understanding the description andintended scope of the present invention.

When describing the compounds, pharmaceutical compositions containingsuch compounds and methods of using such compounds and compositions, thefollowing terms have the following meanings unless otherwise indicated.It should be further understood that the terms “groups” and “radicals”can be considered interchangeable when used herein.

The articles “a” and “an” may be used herein to refer to one or to morethan one (i.e. at least one) of the grammatical objects of the article.By way of example “an analogue” means one analogue or more than oneanalogue.

“Acyl” refers to a radical —C(O)R²⁰, where R²⁰ is hydrogen, alkyl,cycloalkyl, cycloheteroalkyl, aryl, arylalkyl, heteroalkyl, heteroaryl,heteroarylalkyl as defined herein. Representative examples include, butare not limited to, formyl, acetyl, cyclohexylcarbonyl,cyclohexylmethylcarbonyl, benzoyl, benzylcarbonyl and the like.

“Acylamino” refers to a radical —NR²¹C(O)R²², where R²¹ is hydrogen,alkyl, cycloalkyl, cycloheteroalkyl, aryl, arylalkyl, heteroalkyl,heteroaryl, heteroarylalkyl and R²² is hydrogen, alkyl, alkoxy,cycloalkyl, cycloheteroalkyl, aryl, arylalkyl, heteroalkyl, heteroarylor heteroarylalkyl, as defined herein. Representative examples include,but are not limited to, formylamino, acetylamino,cyclohexylcarbonylamino, cyclohexylmethyl-carbonylamino, benzoylamino,benzylcarbonylamino and the like.

“Acyloxy” refers to the group —OC(O)R²³ where R²³ is hydrogen, alkyl,aryl or cycloalkyl.

“Substituted alkenyl” refers to those groups recited in the definitionof “substituted” herein, and particularly refers to an alkenyl grouphaving 1 or more substituents, for instance from 1 to 5 substituents,and particularly from 1 to 3 substituents, selected from the groupconsisting of acyl, acylamino, acyloxy, alkoxy, substituted alkoxy,alkoxycarbonyl, alkoxycarbonylamino, amino, substituted amino,aminocarbonyl, aminocarbonylamino, aminocarbonyloxy, aryl, aryloxy,azido, carboxyl, cyano, cycloalkyl, substituted cycloalkyl, halogen,hydroxyl, keto, nitro, thioalkoxy, substituted thioalkoxy, thioaryloxy,thioketo, thiol, alkyl-S(O)—, aryl-S(O)—, alkyl-S(O)₂— and aryl-S(O)₂—.

“Alkoxy” refers to the group —OR²⁴ where R²⁴ is alkyl. Exemplary alkoxyincludes methoxy, ethoxy, n-propoxy, i-propoxy, n-butoxy, and heptoxy.Particular alkoxy groups are lower alkoxy, i.e. with between 1 and 6carbon atoms.

“Substituted alkoxy” refers to those groups recited in the definition of“substituted” herein, and particularly refers to an alkoxy group having1 or more substituents, for instance from 1 to 5 substituents, andparticularly from 1 to 3 substituents, selected from the groupconsisting of acyl, acylamino, acyloxy, alkoxy, substituted alkoxy,alkoxycarbonyl, alkoxycarbonylamino, amino, substituted amino,aminocarbonyl, aminocarbonylamino, aminocarbonyloxy, aryl, aryloxy,azido, carboxyl, cyano, cycloalkyl, substituted cycloalkyl, halogen,heteroaryl, hydroxyl, keto, nitro, thioalkoxy, substituted thioalkoxy,thioaryloxy, thioketo, thiol, alkyl-S(O)—, aryl-S(O)—, alkyl-S(O)₂— andaryl-S(O)₂—.

“Alkoxycarbonylamino” refers to the group —NR²⁵C(O)OR²⁶, where R²⁵ ishydrogen, alkyl, aryl or cycloalkyl, and R²⁶ is alkyl or cycloalkyl.

“Alkyl” refers to monovalent saturated alkane radical groupsparticularly having up to about 11 carbon atoms, more particularly, from1 to 8 carbon atoms and still more particularly, from 1 to 6 carbonatoms. The hydrocarbon chain may be either straight-chained or branched.This term is exemplified by groups such as methyl, ethyl, n-propyl,isopropyl, n-butyl, iso-butyl, tert-butyl, n-hexyl, n-octyl, tert-octyland the like. The term “lower alkyl” refers to alkyl groups having 1 to6 carbon atoms.

“Substituted alkyl” refers to those groups recited in the definition of“substituted” herein, and particularly refers to an alkyl group having 1or more substituents, for instance from 1 to 5 substituents, andparticularly from 1 to 3 substituents, selected from the groupconsisting of acyl, acylamino, acyloxy, alkoxy, substituted alkoxy,alkoxycarbonyl, alkoxycarbonylamino, amino, substituted amino,aminocarbonyl, aminocarbonylamino, aminocarbonyloxy, aryl, aryloxy,azido, carboxyl, cyano, cycloalkyl, substituted cycloalkyl, halogen,hydroxyl, heteroaryl, keto, nitro, thioalkoxy, substituted thioalkoxy,thioaryloxy, thioketo, thiol, alkyl-S(O)—, aryl-S(O)—, alkyl-S(O)₂—, andaryl-S(O)₂—.

“Alkylene” refers to divalent saturated alkene radical groups having 1to 11 carbon atoms and more particularly 1 to 6 carbon atoms which canbe straight-chained or branched. This term is exemplified by groups suchas methylene (—CH₂—), ethylene (—CH₂CH₂—), the propylene isomers (e.g.,—CH₂CH₂CH₂— and —CH(CH₃)CH₂—), and the like.

“Substituted alkylene” refers to those groups recited in the definitionof “substituted” herein, and particularly refers to an alkylene grouphaving 1 or more substituents, for instance from 1 to 5 substituents,and particularly from 1 to 3 substituents, selected from the groupconsisting of acyl, acylamino, acyloxy, alkoxy, substituted alkoxy,alkoxycarbonyl, alkoxycarbonylamino, amino, substituted amino,aminocarbonyl, amino-carbonylamino, aminocarbonyloxy, aryl, aryloxy,azido, carboxyl, cyano, halogen, hydroxyl, keto, nitro, thioalkoxy,substituted thioalkoxy, thioaryloxy, thioketo, thiol, alkyl-S(O)—,aryl-S(O)—, alkyl-S(O)₂— and aryl-S(O)₂—.

“Alkenyl” refers to monovalent olefinically unsaturated hydrocarbylgroups preferably having 2 to 11 carbon atoms, particularly, from 2 to 8carbon atoms, and more particularly, from 2 to 6 carbon atoms, which canbe straight-chained or branched and having at least 1 and particularlyfrom 1 to 2 sites of olefinic unsaturation. Particular alkenyl groupsinclude ethenyl (—CH═CH₂), n-propenyl (—CH₂CH═CH₂), isopropenyl(—C(CH₃)═CH₂), vinyl and substituted vinyl, and the like.

“Alkenylene” refers to divalent olefinically unsaturated hydrocarbylgroups particularly having up to about 11 carbon atoms and moreparticularly 2 to 6 carbon atoms which can be straight-chained orbranched and having at least 1 and particularly from 1 to 2 sites ofolefinic unsaturation. This term is exemplified by groups such asethenylene (—CH═CH—), the propenylene isomers (e.g., —CH═CHCH₂— and—C(CH₃)═CH— and —CH═C(CH₃)—) and the like.

“Alkynyl” refers to acetylenically or alkynically unsaturatedhydrocarbyl groups particularly having 2 to 11 carbon atoms, and moreparticularly 2 to 6 carbon atoms which can be straight-chained orbranched and having at least 1 and particularly from 1 to 2 sites ofalkynyl unsaturation. Particular non-limiting examples of alkynyl groupsinclude acetylenic, ethynyl propargyl (—CH₂C≡CH), and the like.

“Substituted alkynyl” refers to those groups recited in the definitionof “substituted” herein, and particularly refers to an alkynyl grouphaving 1 or more substituents, for instance from 1 to 5 substituents,and particularly from 1 to 3 substituents, selected from the groupconsisting of acyl, acylamino, acyloxy, alkoxy, substituted alkoxy,alkoxycarbonyl, alkoxycarbonylamino, amino, substituted amino,aminocarbonyl, aminocarbonylamino, aminocarbonyloxy, aryl, aryloxy,azido, carboxyl, cyano, cycloalkyl, substituted cycloalkyl, halogen,hydroxyl, keto, nitro, thioalkoxy, substituted thioalkoxy, thioaryloxy,thioketo, thiol, alkyl-S(O)—, aryl-S(O)—, alkyl-S(O)₂— and aryl-S(O)₂—.

“Alkanoyl” or “acyl” as used herein refers to the group R²⁷—C(O)—, whereR²⁷ is hydrogen or alkyl as defined above.

“Aryl” refers to a monovalent aromatic hydrocarbon group derived by theremoval of one hydrogen atom from a single carbon atom of a parentaromatic ring system. Aryl groups may be monocyclic or a bicyclicfused-ring structure where at least one of the rings is an aromatic ringstructure that particularly contains 6 carbons. Typical aryl groupsinclude, but are not limited to, groups derived from aceanthrylene,acenaphthylene, acephenanthrylene, anthracene, azulene, benzene,chrysene, coronene, fluoranthene, fluorene, hexacene, hexaphene,hexylene, as-indacene, s-indacene, indane, indene, naphthalene,octacene, octaphene, octalene, ovalene, penta 2,4 diene, pentacene,pentalene, pentaphene, perylene, phenalene, phenanthrene, picene,pleiadene, pyrene, pyranthrene, rubicene, triphenylene, trinaphthaleneand the like. Particularly, an aryl group comprises from 6 to 14 carbonatoms. Particularly, the aryl group may contain 6 carbon atoms.Exemplary aryl groups include phenyl and indan-1-one.

“Substituted Aryl” includes those groups recited in the definition of“substituted” herein, and particularly refers to an aryl group that mayoptionally be substituted with 1 or more substituents, for instance from1 to 5 substituents, particularly 1 to 3 substituents, selected from thegroup consisting of acyl, acylamino, acyloxy, alkenyl, substitutedalkenyl, alkoxy, substituted alkoxy, alkoxycarbonyl, alkyl, substitutedalkyl, alkynyl, substituted alkynyl, amino, substituted amino,aminocarbonyl, aminocarbonylamino, aminocarbonyloxy, aryl, aryloxy,azido, carboxyl, cyano, cycloalkyl, substituted cycloalkyl, halogen,hydroxyl, nitro, thioalkoxy, substituted thioalkoxy, thioaryloxy, thiol,alkyl-S(O)—, aryl-S(O)—, alkyl-S(O)₂— and aryl-S(O)₂—.

“Fused Aryl” refers to an aryl having two of its ring carbon in commonwith a second aryl ring or with an aliphatic ring.

“Alkaryl” refers to an aryl group, as defined above, substituted withone or more alkyl groups, as defined above.

“Aralkyl” or “arylalkyl” refers to an alkyl group, as defined above,substituted with one or more aryl groups, as defined above.

“Aryloxy” refers to —O-aryl groups wherein “aryl” is as defined above.

“Alkylamino” refers to the group alkyl-NR²⁸R²⁹, wherein each of R²⁸ andR²⁹ are independently selected from hydrogen and alkyl.

“Arylamino” refers to the group aryl-NR³⁰R³¹, wherein each of R³⁰ andR³¹ are independently selected from hydrogen, aryl and heteroaryl.

“Alkoxyamino” refers to a radical —N(H)OR³² where R³² represents analkyl or cycloalkyl group as defined herein.

“Alkoxycarbonyl” refers to a radical —C(O)-alkoxy where alkoxy is asdefined herein.

“Alkylarylamino” refers to a radical —NR³³R³⁴ where R³³ represents analkyl or cycloalkyl group and R³⁴ is an aryl as defined herein.

“Alkylsulfonyl” refers to a radical —S(O)₂R³⁵ where R³⁵ is an alkyl orcycloalkyl group as defined herein. Representative examples include, butare not limited to, methylsulfonyl, ethylsulfonyl, propylsulfonyl,butylsulfonyl and the like.

“Alkylsulfinyl” refers to a radical —S(O)R³⁵ where R³⁵ is an alkyl orcycloalkyl group as defined herein. Representative examples include, butare not limited to, methylsulfinyl, ethylsulfinyl, propylsulfinyl,butylsulfinyl and the like.

“Alkylthio” refers to a radical —SR³⁵ where R³⁵ is an alkyl orcycloalkyl group as defined herein that may be optionally substituted asdefined herein. Representative examples include, but are not limited to,methylthio, ethylthio, propylthio, butylthio, and the like.

“Amino” refers to the radical —NH₂.

“Substituted amino” refers to those groups recited in the definition of“substituted” herein, and particularly refers to the group —N(R³⁶)₂where each R³⁶ is independently selected from the group consisting ofhydrogen, alkyl, substituted alkyl, alkenyl, substituted alkenyl,alkynyl, substituted alkynyl, aryl, cycloalkyl, substituted cycloalkyl,and where both R groups are joined to form an alkylene group. When bothR groups are hydrogen, —N(R³⁶)₂ is an amino group.

“Aminocarbonyl” refers to the group —C(O)NR³⁷R³⁷ where each R³⁷ isindependently hydrogen, alkyl, aryl and cycloalkyl, or where the R³⁷groups are joined to form an alkylene group.

“Aminocarbonylamino” refers to the group —NR³⁸C(O)NR³⁸R³⁸ where each R³⁸is independently hydrogen, alkyl, aryl or cycloalkyl, or where two Rgroups are joined to form an alkylene group.

“Aminocarbonyloxy” refers to the group —OC(O)NR³⁹R³⁹ where each R³⁹ isindependently hydrogen, alkyl, aryl or cycloalkyl, or where the R groupsare joined to form an alkylene group.

“Arylalkyloxy” refers to an —O-arylalkyl radical where arylalkyl is asdefined herein.

“Arylamino” means a radical —NHR⁴⁰ where R⁴⁰ represents an aryl group asdefined herein.

“Aryloxycarbonyl” refers to a radical —C(O)—O-aryl where aryl is asdefined herein.

“Arylsulfonyl” refers to a radical —S(O)₂R⁴¹ where R⁴¹ is an aryl orheteroaryl group as defined herein.

“Azido” refers to the radical —N₃.

“Bicycloaryl” refers to a monovalent aromatic hydrocarbon group derivedby the removal of one hydrogen atom from a single carbon atom of aparent bicycloaromatic ring system. Typical bicycloaryl groups include,but are not limited to, groups derived from indane, indene, naphthalene,tetrahydronaphthalene, and the like. Particularly, an aryl groupcomprises from 8 to 11 carbon atoms.

“Bicycloheteroaryl” refers to a monovalent bicycloheteroaromatic groupderived by the removal of one hydrogen atom from a single atom of aparent bicycloheteroaromatic ring system. Typical bicycloheteroarylgroups include, but are not limited to, groups derived from benzofuran,benzimidazole, benzindazole, benzdioxane, chromene, chromane, cinnoline,phthalazine, indole, indoline, indolizine, isobenzofuran, isochromene,isoindole, isoindoline, isoquinoline, benzothiazole, benzoxazolc,naphthyridine, benzoxadiazole, pteridine, purine, benzopyran,benzpyrazine, pyridopyrimidine, quinazoline, quinoline, quinolizine,quinoxaline, benzomorphan, tetrahydroisoquinoline, tetrahydroquinoline,and the like. Preferably, the bicycloheteroaryl group is between 9-11membered bicycloheteroaryl, with 5-10 membered heteroaryl beingparticularly preferred. Particular bicycloheteroaryl groups are thosederived from benzothiophene, benzofuran, benzothiazole, indole,quinoline, isoquinoline, benzimidazole, benzoxazole and benzdioxane.

“Carbamoyl” refers to the radical —C(O)N(R⁴²)₂ where each R⁴² group isindependently hydrogen, alkyl, cycloalkyl or aryl, as defined herein,which may be optionally substituted as defined herein. In a specificembodiment, the term “carbamoyl” refers to —C(O)—NH₂. In an alternativeembodiment “carbamoyl lower alkyl” means the radical NH₂CO-lower alkyl-.Particular carbamoyl lower alkyl groups include carbamoylethyl andcarbamoylmethyl.

“Carboxy” refers to the radical —C(O)OH.

“Carboxyamino” refers to the radical —N(H)C(O)OH.

“Compounds of the present invention”, and equivalent expressions, aremeant to embrace the compounds as hereinbefore described, in particularcompounds according to any of the formulae herein recited and/ordescribed, which expression includes the prodrugs, the pharmaceuticallyacceptable salts, and the solvates, e.g., hydrates, where the context sopermits. Similarly, reference to intermediates, whether or not theythemselves are claimed, is meant to embrace their salts, and solvates,where the context so permits.

“Cycloalkylalkyl” refers to a radical in which a cycloalkyl group issubstituted for a hydrogen atom of an alkyl group. Typicalcycloalkylalkyl groups include, but are not limited to,cyclopropylmethyl, cyclobutylmethyl, cyclopentylmethyl,cyclohexylmethyl, cycloheptylmethyl, cyclooctylmethyl, cyclopropylethyl,cyclobutylethyl, cyclopentylethyl, cyclohexylethyl, cycloheptylethyl,and cyclooctylethyl, and the like.

“Heterocycloalkylalkyl” refers to a radical in which a heterocycloalkylgroup is substituted for a hydrogen atom of an alkyl group. Typicalheterocycloalkylalkyl groups include, but are not limited to,pyrrolidinylmethyl, piperidinylmethyl, piperazinylmethyl,morpholinylmethyl, pyrrolidinylethyl, piperidinylethyl,piperazinylethyl, morpholinylethyl, and the like.

“Halo” or “halogen” means fluoro (F), chloro (Cl), bromo (Br), or iodo(I).

“Hydrogen” means in the context of a substituent that —H is present atthe compound position and also includes its isotope, deuterium.

“Lower alkanoyl amino” means an amino group with an organic functionalgroup R—CO—, where R represents a lower alkyl group.

“Lower alkoxy” means 1 to 6 carbon atoms in a linear alkyl chain thatmay be straight or branched, and that is bonded by an oxygen atom.

“Lower alkyl sulfonamide” refers to a lower alkyl amide of sulfonamideof the formula —SO₂NR*R*, where R* is hydrogen or lower alkyl, and atleast one R* is lower alkyl.

“Cycloalkyl” refers to cyclic hydrocarbyl groups having from 3 to about10 carbon atoms and having a single cyclic ring or multiple condensedrings, including fused and bridged ring systems, which optionally can besubstituted with from 1 to 3 alkyl groups. Such cycloalkyl groupsinclude, by way of example, single ring structures such as cyclopropyl,cyclobutyl, cyclopentyl, cyclooctyl, 1-methylcyclopropyl,2-methylcyclopentyl, 2-methylcyclooctyl, and the like, and multiple ringstructures such as adamantanyl, and the like. Particular cycloalkylgroups have between 4 and 7 carbon ring members for example cyclopropyl,cyclobutyl, cyclopentyl, cyclohexyl and cycloheptyl.

“Substituted cycloalkyl” includes those groups recited in the definitionof “substituted” herein, and particularly refers to a cycloalkyl grouphaving 1 or more substituents, for instance from 1 to 5 substituents,and particularly from 1 to 3 substituents, selected from the groupconsisting of acyl, acylamino, acyloxy, alkoxy, substituted alkoxy,alkoxycarbonyl, alkoxycarbonylamino, amino, substituted amino,aminocarbonyl, aminocarbonylamino, aminocarbonyloxy, aryl, aryloxy,azido, carboxyl, cyano, cycloalkyl, substituted cycloalkyl, halogen,hydroxyl, keto, nitro, thioalkoxy, substituted thioalkoxy, thioaryloxy,thioketo, thiol, alkyl-S(O)—, aryl-S(O)—, alkyl-S(O)₂— and aryl-S(O)₂—.

“Cycloalkoxy” refers to the group —OR⁴³ where R⁴³ is cycloalkyl. Suchcycloalkoxy groups include, by way of example, cyclopentoxy, cyclohexoxyand the like.

“Cycloalkenyl” refers to cyclic hydrocarbyl groups having from 3 to 10carbon atoms and having a single cyclic ring or multiple condensedrings, including fused and bridged ring systems and having at least oneand particularly from 1 to 2 sites of olefinic unsaturation. Suchcycloalkenyl groups include, by way of example, single ring structuressuch as cyclohexenyl, cyclopentenyl, cyclopropenyl, and the like.

“Substituted cycloalkenyl” refers to those groups recited in thedefinition of “substituted” herein, and particularly refers to acycloalkenyl group having 1 or more substituents, for instance from 1 to5 substituents, and particularly from 1 to 3 substituents, selected fromthe group consisting of acyl, acylamino, acyloxy, alkoxy, substitutedalkoxy, alkoxycarbonyl, alkoxycarbonylamino, amino, substituted amino,aminocarbonyl, aminocarbonylamino, aminocarbonyloxy, aryl, aryloxy,azido, carboxyl, cyano, cycloalkyl, substituted cycloalkyl, halogen,hydroxyl, keto, nitro, thioalkoxy, substituted thioalkoxy, thioaryloxy,thioketo, thiol, alkyl-S(O)—, aryl-S(O)—, alkyl-S(O)₂— and aryl-S(O)₂—.

“Fused Cycloalkenyl” refers to a cycloalkenyl having two of its ringcarbon atoms in common with a second aliphatic or aromatic ring andhaving its olefinic unsaturation located to impart aromaticity to thecycloalkenyl ring.

“Cyanato” refers to the radical —OCN.

“Cyano” refers to the radical —CN.

“Dialkylamino” means a radical —NR⁴⁴R⁴⁵ where R⁴⁴ and R⁴⁵ independentlyrepresent an alkyl, substituted alkyl, aryl, substituted aryl,cycloalkyl, substituted cycloalkyl, cycloheteroalkyl, substitutedcycloheteroalkyl, heteroaryl, or substituted heteroaryl group as definedherein.

“Ethenyl” refers to substituted or unsubstituted —(C═C)—.

“Ethylene” refers to substituted or unsubstituted —(C—C)—.

“Ethynyl” refers to —(C≡C)—.

“Halo” or “halogen” refers to fluoro, chloro, bromo and iodo. Preferredhalo groups are either fluoro or chloro.

“Hydroxy” refers to the radical —OH.

“Nitro” refers to the radical —NO₂.

“Substituted” refers to a group in which one or more hydrogen atoms areeach independently replaced with the same or different substituent(s).Typical substituents include, but are not limited to, —X, —R⁴⁶, —O⁻, ═O,—OR⁴⁶, —SR⁴⁶, —S⁻, ═S, —NR⁴⁶R⁴⁷, ═NR⁴⁶, —CX₃, —CF₃, —CN, —OCN, —SCN,—NO, —NO₂, ═N₂, —N₃, —S(O)₂O⁻, —S(O)₂OH, —S(O)₂R⁴⁶, —OS(O₂)O⁻,—OS(O)₂R⁴⁶, —P(O)(O⁻)₂, —P(O)(OR⁴⁶)(O⁻), —OP(O)(OR⁴⁶)(OR⁴⁷), —C(O)R⁴⁶,—C(S)R⁴⁶, —C(O)OR⁴⁶, —C(O)NR⁴⁶R⁴⁷, —C(O)O⁻, —C(S)OR⁴⁶, —NR⁴⁸C(O)NR⁴⁶R⁴⁷,—NR⁴⁸C(S)NR⁴⁶R⁴⁷, —NR⁴⁹C(NR⁴⁸)NR⁴⁶R⁴⁷ and —C(NR⁴⁸)NR⁴⁶R⁴⁷, where each Xis independently a halogen; each R⁴⁶, R⁴⁷, R⁴⁸ and R⁴⁹ are independentlyhydrogen, alkyl, substituted alkyl, aryl, substituted aryl, arylalkyl,substituted alkyl, cycloalkyl, substituted alkyl, cycloheteroalkyl,substituted cycloheteroalkyl, heteroalkyl, substituted heteroalkyl,heteroaryl, substituted heteroaryl, heteroarylalkyl, substitutedheteroarylalkyl, —NR⁵⁰R⁵¹, —C(O)R⁵⁰ or —S(O)₂R⁵⁰ or optionally R⁵⁰ andR⁵¹ together with the atom to which they are both attached form acycloheteroalkyl or substituted cycloheteroalkyl ring; and R⁵⁰ and R⁵¹are independently hydrogen, alkyl, substituted alkyl, aryl, substitutedalkyl, arylalkyl, substituted alkyl, cycloalkyl, substituted alkyl,cycloheteroalkyl, substituted cycloheteroalkyl, heteroalkyl, substitutedheteroalkyl, heteroaryl, substituted heteroaryl, heteroarylalkyl orsubstituted heteroarylalkyl.

Examples of representative substituted aryls include the following

In these formulae one of R⁵² and R⁵³ may be hydrogen and at least one ofR⁵² and R⁵³ is each independently selected from alkyl, alkenyl, alkynyl,cycloheteroalkyl, alkanoyl, alkoxy, aryloxy, heteroaryloxy, alkylamino,arylamino, heteroarylamino, NR⁵⁴COR⁵⁵, NR⁵⁴SOR⁵⁵, NR⁵⁴SO₂R⁵⁷, COO-alkyl,COO-aryl, CONR⁵⁴R⁵⁵, CONR⁵⁴OR⁵⁵, NR⁵⁴R⁵⁵, SO₂NR⁵⁴R⁵⁵, S-alkyl, S-alkyl,SO-alkyl, SO₂-alkyl, S-aryl, SO-aryl, SO₂-aryl; or R⁵² and R⁵³ may bejoined to form a cyclic ring (saturated or unsaturated) from 5 to 8atoms, optionally containing one or more heteroatoms selected from thegroup N, O or S. R⁵⁴, R⁵⁵, and R⁵⁶ are independently hydrogen, alkyl,alkenyl, alkynyl, perfluoroalkyl, cycloalkyl, cycloheteroalkyl, aryl,substituted aryl, heteroaryl, substituted or hetero alkyl or the like.

“Hetero” when used to describe a compound or a group present on acompound means that one or more carbon atoms in the compound or grouphave been replaced by a nitrogen, oxygen, or sulfur heteroatom. Heteromay be applied to any of the hydrocarbyl groups described above such asalkyl, e.g. heteroalkyl, cycloalkyl, e.g. heterocycloalkyl, aryl, e.g.heteroaryl, cycloalkenyl, heterocycloalkenyl, and the like having from 1to 5, and especially from 1 to 3 heteroatoms.

“Heteroaryl” refers to a monovalent heteroaromatic group derived by theremoval of one hydrogen atom from a single atom of a parentheteroaromatic ring system. The heteroaryl group may be a monocyclicgroup (in which case it will typically be a 5 to 7, more typically a 5or 6 membered ring), alternatively the heteroaryl group may be abicycloheteroaryl group in particular a fused ring system comprising 2fused 5-membered rings, a fused 5 and 6 membered ring or two fused 6membered rings, where the heteroaryl group comprises fused rings atleast one of said rings should contain a heteroatom and at least onesaid rings should be aromatic (both requirements may or may not befulfilled in the same ring). The heteroaryl group can be, for example, afive membered or six membered monocyclic ring which may contain up toabout four heteroatoms typically selected from nitrogen, sulphur andoxygen. Typically the heteroaryl ring will contain up to 4 heteroatoms,more typically up to 3 heteroatoms, more usually up to 2, for example asingle heteroatom. In one embodiment, the heteroaryl ring contains atleast one ring nitrogen atom. The nitrogen atoms in the heteroaryl ringscan be basic, as in the case of an imidazole or pyridine, or essentiallynon-basic as in the case of an indole or pyrrole nitrogen. In generalthe number of basic nitrogen atoms present in the heteroaryl group,including any amino group substituents of the ring, will be less thanfive. Typical heteroaryl groups include, but are not limited to, groupsderived from acridine, arsindole, carbazole, β-carboline, chromane,chromene, cinnoline, furan, imidazole, indazole, indole, indoline,indolizine, isobenzofuran, isochromene, isoindole, isoindoline,isoquinoline, isothiazole, isoxazole, naphthyridine, oxadiazole,oxazole, perimidine, phenanthridine, phenanthroline, phenazine,phthalazine, pteridine, purine, pyran, pyrazine, pyrazole, pyridazine,pyridine, pyrimidine, pyrrole, pyrrolizine, quinazoline, quinoline,quinolizine, quinoxaline, tetrazole, thiadiazole, thiazole, thiophene,triazole, xanthene, and the like. Particularly, the heteroaryl group isbetween 5-15 membered heteroaryl, with 5-10 membered heteroaryl beingparticular groups. Particular heteroaryl groups are those derived fromthiophene, pyrrole, benzothiophene, benzofuran, indole, pyridine,quinoline, imidazole, oxazole and pyrazine. Particularly, examples offive membered heteroaryl groups include but are not limited to pyrrole,furan, thiophene, imidazole, furazan, oxazole, oxadiazole, oxatriazole,isoxazole, thiazole, isothiazole, pyrazole, triazole and tetrazolegroups. Particularly, examples of six membered heteroaryl groups includebut are not limited to pyridine, pyrazine, pyridazine, pyrimidine andtriazine.

Examples of representative heteroaryls include the following:

wherein each Y is selected from carbonyl, N, NR⁵⁸, O, and S; and R⁵⁸ isindependently hydrogen, alkyl, cycloalkyl, cycloheteroalkyl, aryl,heteroaryl, heteroalkyl or the like.

As used herein, the term “cycloheteroalkyl” refers to a stableheterocyclic non-aromatic ring and fused rings containing one or moreheteroatoms independently selected from N, O and S. A fused heterocyclicring system may include carbocyclic rings and need only include oneheterocyclic ring. Examples of heterocyclic rings include, but are notlimited to, piperazinyl, homopiperazinyl, piperidinyl and morpholinyl,and are shown in the following illustrative examples:

wherein each X is selected from CR⁵⁸, CR⁵⁸ ₂, NR⁵⁸, O and S; and each Yis selected from NR⁵⁸, O and S; and R⁵⁸ is independently hydrogen,alkyl, cycloalkyl, cycloheteroalkyl, aryl, heteroaryl, heteroalkyl orthe like. These cycloheteroalkyl rings may be optionally substitutedwith one or more groups selected from the group consisting of acyl,acylamino, acyloxy, alkoxy, substituted alkoxy, alkoxycarbonyl,alkoxycarbonylamino, amino, substituted amino, aminocarbonyl,aminocarbonylamino, aminocarbonyloxy, aryl, aryloxy, azido, carboxyl,cyano, cycloalkyl, substituted cycloalkyl, halogen, hydroxyl, keto,nitro, thioalkoxy, substituted thioalkoxy, thioaryloxy, thioketo, thiol,alkyl-S(O)—, aryl-S(O)—, alkyl-S(O)₂— and aryl-S(O)₂—. Substitutinggroups include carbonyl or thiocarbonyl which provide, for example,lactam and urea derivatives.

Examples of representative cycloheteroalkenyls include the following:

wherein each X is selected from CR⁵⁸, CR⁵⁸ ₂, NR⁵⁸, O and S; and each Yis selected from carbonyl, N, NR⁵⁸, O and S; and R⁵⁸ is independentlyhydrogen, alkyl, cycloalkyl, cycloheteroalkyl, aryl, heteroaryl,heteroalkyl or the like.

Examples of representative aryls having hetero atoms containingsubstitution include the following:

wherein each X is selected from CR⁵⁸, CR⁵⁸ ₂, NR⁵⁸, O and S; and each Yis selected from carbonyl, NR⁵⁸, O and S; and R⁵⁸ is independentlyhydrogen, alkyl, cycloalkyl, cycloheteroalkyl, aryl, heteroaryl,heteroalkyl or the like.

“Hetero substituent” refers to a halo, O, S or N atom-containingfunctionality that may be present as an R⁴ in a R⁴C group present assubstituents directly on a ring atom of the compounds provided herein ormay be present as a substituent in the “substituted” aryl and aliphaticgroups present in the compounds.

Examples of hetero substituents include:

-   -   -halo,    -   —NO₂, —NH₂, —NHR⁵⁹, —N(R⁵⁹)₂,    -   —NRCOR, —NR⁵⁹SOR⁵⁹, —NR⁵⁹SO₂R⁵⁹, OH, CN,    -   —CO₂H,    -   —R⁵⁹—OH, —O—R⁵⁹, —COOR⁵⁹,    -   —CON(R⁵⁹)₂, —CONROR⁵⁹,    -   —SO₃H, —R⁵⁹—S, —SO₂N(R⁵⁹)₂,    -   —S(O)R⁵⁹, —S(O)₂R⁵⁹        wherein each R⁵⁹ is independently an aryl or aliphatic,        optionally with substitution. Among hetero substituents        containing R⁵⁹ groups, preference is given to those materials        having aryl and alkyl R⁵⁹ groups as defined herein. Preferred        hetero substituents are those listed above.

“Hydrogen bond donor” group refers to a group containing O—H, or N—Hfunctionality. Examples of “hydrogen bond donor” groups include —OH,—NH₂, and —NH—R^(59a) and wherein R^(59a) is alkyl, acyl, cycloalkyl,aryl, or heteroaryl.

“Dihydroxyphosphoryl” refers to the radical —PO(OH)₂.

“Substituted dihydroxyphosphoryl” refers to those groups recited in thedefinition of “substituted” herein, and particularly refers to adihydroxyphosphoryl radical wherein one or both of the hydroxyl groupsare substituted. Suitable substituents are described in detail below.

“Aminohydroxyphosphoryl” refers to the radical —PO(OH)NH₂.

“Substituted aminohydroxyphosphoryl” refers to those groups recited inthe definition of “substituted” herein, and particularly refers to anaminohydroxyphosphoryl wherein the amino group is substituted with oneor two substituents. Suitable substituents are described in detailbelow. In certain embodiments, the hydroxyl group can also besubstituted.

“Nitrogen-Containing Heterocycloalkyl” group means a 4 to 7 memberednon-aromatic cyclic group containing at least one nitrogen atom, forexample, but without limitation, morpholine, piperidine (e.g.2-piperidinyl, 3-piperidinyl and 4-piperidinyl), pyrrolidine (e.g.2-pyrrolidinyl and 3-pyrrolidinyl), azetidine, pyrrolidone, imidazoline,imidazolidinone, 2-pyrazoline, pyrazolidine, piperazine, and N-alkylpiperazines such as N-methyl piperazine. Particular examples includeazetidine, piperidone and piperazone.

“Thioalkoxy” refers to the group —SR⁶⁰ where R⁶⁰ is alkyl.

“Substituted thioalkoxy” refers to those groups recited in thedefinition of “substituted” herein, and particularly refers to athioalkoxy group having 1 or more substituents, for instance from 1 to 5substituents, and particularly from 1 to 3 substituents, selected fromthe group consisting of acyl, acylamino, acyloxy, alkoxy, substitutedalkoxy, alkoxycarbonyl, alkoxycarbonylamino, amino, substituted amino,aminocarbonyl, aminocarbonylamino, aminocarbonyloxy, aryl, aryloxy,azido, carboxyl, cyano, cycloalkyl, substituted cycloalkyl, halogen,hydroxyl, keto, nitro, thioalkoxy, substituted thioalkoxy, thioaryloxy,thioketo, thiol, alkyl-S(O)—, aryl-S(O)—, alkyl-S(O)₂— and aryl-S(O)₂—.

“Sulfanyl” refers to the radical HS—. “Substituted sulfanyl” refers to aradical such as RS— wherein R is any substituent described herein. Inparticular, R is substituted or unsubstituted alkyl substituted orunsubstituted aryl or substituted or unsubstituted heteroaryl.

“Sulfinyl” refers to the divalent radical —S(O)—. “Substituted sulfinyl”refers to a radical such as —SOR^(61a), wherein R^(61a) is anysubstituent described herein. In particular, R^(61a) is substituted orunsubstituted alkyl, substituted or unsubstituted aryl or substituted orunsubstituted heteroaryl.

“Aminosulfonyl” or “Sulfonamide” refers to the radical H₂N(O₂)S—, and“substituted aminosulfonyl” “substituted sulfonamide” refers to aradical such as R⁶² ₂N(O₂)S— wherein each R⁶² is independently anysubstituent described herein.

“Sulfonyl” refers to the divalent radical —S(O₂)—. “Substitutedsulfonyl” refers to a radical such as —S(O₂)R⁶¹, wherein R⁶¹ is anysubstituent described herein. In particular, R⁶¹ is substituted orunsubstituted alkyl or substituted or unsubstituted aryl.

“Aminosulfonyl” or “Sulfonamide” refers to the radical H₂N(O₂)S—, and“substituted aminosulfonyl” “substituted sulfonamide” refers to aradical such as R⁶² ₂N(O₂)S— wherein each R⁶² is independently anysubstituent described herein.

“Sulfonamide” refers to a group of compounds containing the chemicalgroup —SO₂NH₂.

“Sulfone” refers to the group —SO₂R⁶³. In particular embodiments, R⁶³ isselected from lower alkyl, alkyl, aryl and heteroaryl.

“Sulfo” or “sulfonic acid” refers to a radical such as —SO₃H.

“Substituted Sulfo” or “sulfonic acid ester” refers to a radical such as—SO₃R^(61b) wherein R^(61b) is substituted or unsubstituted alkyl orsubstituted or unsubstituted aryl.

“Thioaryloxy” refers to the group —SR⁶⁴ where R⁶⁴ is aryl.

“Thioketo” refers to the group ═S.

“Thiol” refers to the group —SH.

One having ordinary skill in the art of organic synthesis will recognizethat the maximum number of heteroatoms in a stable, chemically feasibleheterocyclic ring, whether it is aromatic or non aromatic, is determinedby the size of the ring, the degree of unsaturation and the valence ofthe heteroatoms. In general, a heterocyclic ring may have one to fourheteroatoms so long as the heteroaromatic ring is chemically feasibleand stable.

“Pharmaceutically acceptable” means approved by a regulatory agency ofthe Federal or a state government or listed in the U.S. Pharmacopoeia orother generally recognized pharmacopoeia for use in animals, and moreparticularly in humans.

“Pharmaceutically acceptable vehicle” refers to a diluent, adjuvant,excipient or carrier with which a compound of the invention isadministered.

“Pharmaceutically acceptable salt” refers to the non-toxic, inorganicand organic acid addition salts, and base addition salts, of compoundsof the present invention, in particular they are pharmaceuticallyacceptable and possess the desired pharmacological activity of theparent compound. These salts can be prepared in situ during the finalisolation and purification of compounds useful in the present invention.Such salts include: (1) acid addition salts, formed with inorganic acidssuch as hydrochloric acid, hydrobromic acid, sulfuric acid, nitric acid,phosphoric acid, and the like; or formed with organic acids such asacetic acid, propionic acid, hexanoic acid, cyclopentanepropionic acid,glycolic acid, pyruvic acid, lactic acid, malonic acid, succinic acid,malic acid, maleic acid, fumaric acid, tartaric acid, citric acid,benzoic acid, 3-(4-hydroxybenzoyl)benzoic acid, cinnamic acid, mandelicacid, methanesulfonic acid, ethanesulfonic acid, 1,2-ethane-disulfonicacid, 2-hydroxyethanesulfonic acid, benzenesulfonic acid,4-chlorobenzenesulfonic acid, 2-naphthalenesulfonic acid,4-toluenesulfonic acid, camphorsulfonic acid,4-methylbicyclo[2.2.2]-oct-2-ene-1-carboxylic acid, glucoheptonic acid,3-phenylpropionic acid, trimethylacetic acid, tertiary butylacetic acid,lauryl sulfuric acid, gluconic acid, glutamic acid, hydroxynaphthoicacid, salicylic acid, stearic acid, muconic acid, and the like; or (2)salts formed when an acidic proton present in the parent compound eitheris replaced by a metal ion, e.g., an alkali metal ion, an alkaline earthion, or an aluminum ion; or coordinates with an organic base such asethanolamine, diethanolamine, triethanolamine, N-methylglucamine and thelike. Salts further include, by way of example only, sodium, potassium,calcium, magnesium, ammonium, tetraalkylammonium, and the like; and whenthe compound contains a basic functionality, salts of non toxic organicor inorganic acids, such as hydrochloride, hydrobromide, tartrate,mesylate, acetate, maleate, oxalate and the like. The term“pharmaceutically acceptable cation” refers to a non toxic, acceptablecationic counter-ion of an acidic functional group. Such cations areexemplified by sodium, potassium, calcium, magnesium, ammonium,tetraalkylammonium cations, and the like.

“Prodrugs” refers to compounds, including derivatives of the compoundsof the invention, which have cleavable groups and become by solvolysisor under physiological conditions the compounds of the invention whichare pharmaceutically active in vivo. Such examples include, but are notlimited to, choline ester derivatives and the like, N-alkylmorpholineesters and the like. “Solvate” means a physical association of acompound useful in this invention with one or more solvent molecules.This physical association includes hydrogen bonding. In certaininstances the solvate will be capable of isolation, for example when oneor more solvent molecules are incorporated in the crystal lattice of thecrystalline solid. “Solvate” encompasses both solution-phase andisolable solvates. The compounds of the invention may be prepared e.g.in crystalline form and may be solvated or hydrated. Suitable solvatesinclude pharmaceutically acceptable solvates, such as hydrates, andfurther include both stoichiometric solvates and non-stoichiometricsolvates. Conventional solvents include water, ethanol, acetic acid andthe like, therefore, representative solvates include hydrates,ethanolates and methanolates.

“Subject” refers to humans and non-human mammals. In certainembodiments, a subject is a human.

“Therapeutically effective amount” means the amount of a compound that,when administered to a subject for treating a disease, is sufficient toeffect such treatment for the disease. The “therapeutically effectiveamount” can vary depending on the compound, the disease and itsseverity, and the age, weight, etc., of the subject to be treated.

Other derivatives of the compounds of this invention have activity inboth their acid and acid derivative forms, but in the acid sensitiveform often offers advantages of solubility, tissue compatibility, ordelayed release in the mammalian organism (see, Bundgard, H., Design ofProdrugs, pp. 7-9, 21-24, Elsevier, Amsterdam 1985). Prodrugs includeacid derivatives well know to practitioners of the art, such as, forexample, esters prepared by reaction of the parent acid with a suitablealcohol, or amides prepared by reaction of the parent acid compound witha substituted or unsubstituted amine, or acid anhydrides, or mixedanhydrides. Simple aliphatic or aromatic esters, amides and anhydridesderived from acidic groups pendant on the compounds of this inventionare particular prodrugs. In some cases it is desirable to prepare doubleester type prodrugs such as (acyloxy)alkyl esters or((alkoxycarbonyl)oxy)alkylesters. Particularly the C₁ to C₈ alkyl, C₂-C₈alkenyl, aryl, C₇-C₁₂ substituted aryl, and C₇-C₁₂ arylalkyl esters ofthe compounds of the invention.

“Isotopic variant” refers to a compound that contains unnaturalproportions of isotopes at one or more of the atoms that constitute suchcompound. For example, an “isotopic variant” of a compound can containone or more non-radioactive isotopes, such as for example, deuterium (²Hor D), carbon 13 (¹³C), nitrogen-15 (¹⁵N), or the like. It will beunderstood that, in a compound where such isotopic substitution is made,the following atoms, where present, may vary, so that for example, anyhydrogen may be 2H/D, any carbon may be ¹³C, or any nitrogen may be ¹⁵N,and that the presence and placement of such atoms may be determinedwithin the skill of the art. Likewise, the invention may include thepreparation of isotopic variants with radioisotopes, in the instance forexample, where the resulting compounds may be used for drug and/orsubstrate tissue distribution studies. The radioactive isotopes tritium,i.e. ³H, and carbon-14, i.e. ¹⁴C, are particularly useful for thispurpose in view of their ease of incorporation and ready means ofdetection. Further, compounds may be prepared that are substituted withpositron emitting isotopes, such as ¹¹C, ¹⁸F, ¹⁵O and ¹³N, and would beuseful in Positron Emission Topography (PET) studies for examiningsubstrate receptor occupancy. All isotopic variants of the compoundsprovided herein, radioactive or not, are intended to be encompassedwithin the scope of the invention.

It is also to be understood that compounds that have the same molecularformula but differ in the nature or sequence of bonding of their atomsor the arrangement of their atoms in space are termed “isomers”. Isomersthat differ in the arrangement of their atoms in space are termed“stereoisomers”.

Stereoisomers that are not mirror images of one another are termed“diastereomers” and those that are non-superimposable mirror images ofeach other are termed “enantiomers”. When a compound has an asymmetriccenter, for example, it is bonded to four different groups, a pair ofenantiomers is possible. An enantiomer can be characterized by theabsolute configuration of its asymmetric center and is described by theR- and S-sequencing rules of Cahn and Prelog, or by the manner in whichthe molecule rotates the plane of polarized light and designated asdextrorotatory or levorotatory (i.e., as (+) or (−)-isomersrespectively). A chiral compound can exist as either individualenantiomer or as a mixture thereof. A mixture containing equalproportions of the enantiomers is called a “racemic mixture”.

As used herein a pure enantiomeric compound is substantially free fromother enantiomers or stereoisomers of the compound (i.e., inenantiomeric excess). In other words, an “S” form of the compound issubstantially free from the “R” form of the compound and is, thus, inenantiomeric excess of the “R” form. The term “enantiomerically pure” or“pure enantiomer” denotes that the compound comprises more than 75% byweight, more than 80% by weight, more than 85% by weight, more than 90%by weight, more than 91% by weight, more than 92% by weight, more than93% by weight, more than 94% by weight, more than 95% by weight, morethan 96% by weight, more than 97% by weight, more than 98% by weight,more than 98.5% by weight, more than 99% by weight, more than 99.2% byweight, more than 99.5% by weight, more than 99.6% by weight, more than99.7% by weight, more than 99.8% by weight or more than 99.9% by weight,of the enantiomer. In certain embodiments, the weights are based upontotal weight of all enantiomers or stereoisomers of the compound.

As used herein and unless otherwise indicated, the term“enantiomerically pure R-compound” refers to at least about 80% byweight R-compound and at most about 20% by weight S-compound, at leastabout 90% by weight R-compound and at most about 10% by weightS-compound, at least about 95% by weight R-compound and at most about 5%by weight S-compound, at least about 99% by weight R-compound and atmost about 1% by weight S-compound, at least about 99.9% by weightR-compound or at most about 0.1% by weight S-compound. In certainembodiments, the weights are based upon total weight of compound.

As used herein and unless otherwise indicated, the term“enantiomerically pure S-compound” or “S-compound” refers to at leastabout 80% by weight S-compound and at most about 20% by weightR-compound, at least about 90% by weight S-compound and at most about10% by weight R-compound, at least about 95% by weight S-compound and atmost about 5% by weight R-compound, at least about 99% by weightS-compound and at most about 1% by weight R-compound or at least about99.9% by weight S-compound and at most about 0.1% by weight R-compound.In certain embodiments, the weights are based upon total weight ofcompound.

In the compositions provided herein, an enantiomerically pure compoundor a pharmaceutically acceptable salt, solvate, hydrate or prodrugthereof can be present with other active or inactive ingredients. Forexample, a pharmaceutical composition comprising enantiomerically pureR-compound can comprise, for example, about 90% excipient and about 10%enantiomerically pure R-compound. In certain embodiments, theenantiomerically pure R-compound in such compositions can, for example,comprise, at least about 95% by weight R-compound and at most about 5%by weight S-compound, by total weight of the compound. For example, apharmaceutical composition comprising enantiomerically pure S-compoundcan comprise, for example, about 90% excipient and about 10%enantiomerically pure S-compound. In certain embodiments, theenantiomerically pure S-compound in such compositions can, for example,comprise, at least about 95% by weight S-compound and at most about 5%by weight R-compound, by total weight of the compound. In certainembodiments, the active ingredient can be formulated with little or noexcipient or carrier.

“Tautomers” refer to compounds that are interchangeable forms of aparticular compound structure, and that vary in the displacement ofhydrogen atoms and electrons. Thus, two structures may be in equilibriumthrough the movement of it electrons and an atom (usually H). Forexample, enols and ketones are tautomers because they are rapidlyinterconverted by treatment with either acid or base. Another example oftautomerism is the aci- and nitro-forms of phenylnitromethane, that arelikewise formed by treatment with acid or base.

Tautomeric forms may be relevant to the attainment of the optimalchemical reactivity and biological activity of a compound of interest.

The compounds of this invention may possess one or more asymmetriccenters; such compounds can therefore be produced as individual (R)- or(S)-stereoisomers or as mixtures thereof. Unless indicated otherwise,the description or naming of a particular compound in the specificationand claims is intended to include both individual enantiomers andmixtures, racemic or otherwise, thereof. The methods for thedetermination of stereochemistry and the separation of stereoisomers arewell-known in the art.

“Subject” includes humans. The terms “human”, “patient” and “subject”are used interchangeably herein.

“Prophylaxis” means a measure taken for the prevention of a disease.

“Preventing” or “prevention” refers to a reduction in risk of acquiringa disease or disorder (i.e., causing at least one of the clinicalsymptoms of the disease not to develop in a subject that may be exposedto or predisposed to the disease but does not yet experience or displaysymptoms of the disease).

“Treating” or “treatment” of any disease or disorder refers, in oneembodiment, to ameliorating the disease or disorder (i.e., arresting orreducing the development of the disease or at least one of the clinicalsymptoms thereof). In another embodiment “treating” or “treatment”refers to ameliorating at least one physical parameter, which may not bediscernible by the subject. In yet another embodiment, “treating” or“treatment” refers to modulating the disease or disorder, eitherphysically, (e.g., stabilization of a discernible symptom),physiologically, (e.g., stabilization of a physical parameter), or both.In yet another embodiment, “treating” or “treatment” refers to delayingthe onset of the disease or disorder.

“Therapeutically effective amount” means that amount of a drug orpharmaceutical agent that will elicit the biological or medical responseof a subject that is being sought by a medical doctor or otherclinician. The “therapeutically effective amount” can vary depending onthe compound, the disease and its severity, and the age, weight, etc.,of the subject to be treated.

Other derivatives of the compounds provided herein can have activity inboth their acid and acid derivative forms, but in the acid sensitiveform often offers advantages of solubility, tissue compatibility, ordelayed release in the mammalian organism (see, Bundgard, H., Design ofProdrugs, pp. 7-9, 21-24, Elsevier, Amsterdam 1985). Prodrugs includeacid derivatives well know to practitioners of the art, such as, forexample, esters prepared by reaction of the parent acid with a suitablealcohol, or amides prepared by reaction of the parent acid compound witha substituted or unsubstituted amine, or acid anhydrides, or mixedanhydrides. Simple aliphatic or aromatic esters, amides and anhydridesderived from acidic groups pendant on the compounds provided herein arepreferred prodrugs. In some cases it is desirable to prepare doubleester type prodrugs such as (acyloxy)alkyl esters or((alkoxycarbonyl)oxy)alkylesters. Preferred are the C₁ to C₈ alkyl,C₂-C₈ alkenyl, aryl, C₇-C₁₂ substituted aryl, and C₇-C₁₂ arylalkylesters of the compounds provided herein.

The Compounds

In certain aspects, provided herein are fused heterocyclic compoundsuseful for preventing and/or treating a broad range of conditions, amongthem, arthritis, Parkinson's disease, Alzheimer's disease, stroke,uveitis, asthma, myocardial infarction, the treatment and prophylaxis ofpain syndromes (acute and chronic or neuropathic), traumatic braininjury, acute spinal cord injury, neurodegenerative disorders, alopecia(hair loss), inflammatory bowel disease and autoimmune disorders orconditions in mammals.

In one aspect, provided herein are fused heterocyclic compoundsaccording to formula 1, or 2:

wherein

-   -   R¹ is cycloalkyl, cycloheteroalkyl, aryl or heteroaryl        unsubstituted or substituted with one or more R⁴ groups;    -   R² is H, substituted or unsubstituted C₁-C₆ alkyl or cycloalkyl;    -   each R³ and R⁴ is independently selected from the group        consisting of H, alkyl, acyl, acylamino, alkylamino, alkythio,        alkoxy, alkoxycarbonyl, alkylarylamino, arylalkyloxy,        arylalkyloxy, amino, aryl, arylalkyl, sulfo, substituted sulfo,        substituted sulfonyl, substituted sulfinyl, substituted        sulfanyl, azido, carbamoyl, carboxyl, cyano, cycloalkyl,        cycloheteroalkyl, dialkylamino, halo, heteroaryloxy, heteroaryl,        heteroalkyl, hydroxy, nitro, and thiol; m is 1, 2, 3 or 4; or    -   a pharmaceutically acceptable salt, solvate, prodrug,        stereoisomer, tautomer or isotopic variant thereof.

In certain embodiments, R³ is halo, substituted or unsubstituted C₁-C₆alkyl or cycloalkyl.

In another aspect, provided herein are fused heterocyclic compoundsaccording to formula 3a or 3b:

wherein

-   -   R¹ is cycloalkyl, cycloheteroalkyl, aryl or heteroaryl        unsubstituted or substituted with one or more R⁴ groups;    -   R² is H, substituted or unsubstituted C₁-C₆ alkyl or cycloalkyl;    -   each R³ and R⁴ is independently selected from the group        consisting of H, alkyl, acyl, acylamino, alkylamino, alkythio,        alkoxy, alkoxycarbonyl, alkylarylamino, arylalkyloxy,        arylalkyloxy, amino, aryl, arylalkyl, sulfo, substituted sulfo,        substituted sulfonyl, substituted sulfinyl, substituted        sulfanyl, azido, carbamoyl, carboxyl, cyano, cycloalkyl,        cycloheteroalkyl, dialkylamino, halo, heteroaryloxy, heteroaryl,        heteroalkyl, hydroxy, nitro, and thiol; m is 1, 2, 3 or 4; or    -   a pharmaceutically acceptable salt, solvate, prodrug,        stereoisomer, tautomer or isotopic variant thereof.

In certain embodiments, the compound is according to formula 1, 2, 3a or3b.

In one embodiment, with respect to formulae 1-3b, R² is H.

In another embodiment, with respect to formulae 1-3b, R² is other thanH.

In certain embodiments, with respect to formulae 1-3b, R² is substitutedor unsubstituted C₁-C₆ alkyl or cycloalkyl; and the compounds areenantiomerically pure. In certain embodiments, provided arepharmaceutical compositions comprising enantiomerically pure compoundsaccording to formula 1, 2, 3a or 3b. In certain embodiments, providedare methods of treatment that comprise administering an enantiomericallypure compound according to formula 1, 2, 3a or 3b or a pharmaceuticalcomposition comprising an enantiomerically pure compound according toformula 1, 2, 3a or 3b.

In some embodiments, with respect to formulae 1-3b, R¹ is an aryl orheteroaryl group.

In some embodiments, with respect to formulae 1-3b, R¹ is a cycloalkylor cycloheteroalkyl group.

In some embodiments, with respect to formulae 1-3b, R¹ is selected fromsubstituted or unsubstituted

In some embodiments, with respect to formulae 1-3b, R¹ is selected fromsubstituted or unsubstituted

In certain embodiments, with respect to formulae 1-3b, R¹ is selectedfrom substituted

In some embodiments, with respect to formulae 1-3b, R¹ is selected fromsubstituted or unsubstituted aryl, substituted or unsubstitutedheteroaryl, substituted or unsubstituted cycloalkyl, substituted orunsubstituted cycloheteroalkyl, substituted or unsubstitutedcycloalkenyl, substituted or unsubstituted cycloheteroalkenyl,substituted or unsubstituted bicycloalkyl, substituted or unsubstitutedbicycloheteroalkyl, substituted or unsubstituted bicycloalkenyl,substituted or unsubstituted bicycloheteroalkenyl, substituted orunsubstituted bicycloaryl, and substituted or unsubstitutedbicycloheteroaryl.

In some embodiments, with respect to formulae 1-3b, R¹ is selected fromsubstituted or unsubstituted quinolinyl, isoquinolinyl, quinoxaline,methylenedioxyphenyl, imidazopyridyl, benzoxazolyl, and indolyl.

In some embodiments, with respect to formulae 1-3b, R¹ is selected fromunsubstituted quinolinyl, isoquinolinyl, quinoxaline,methylenedioxyphenyl, imidazopyridyl, benzoxazolyl, and indolyl.

In some embodiments, with respect to formulae 1-3b, R¹ is selected fromunsubstituted quinolinyl, isoquinolinyl, and quinoxaline.

In some embodiments, with respect to formulae 1-3b, R¹ is selected fromquinolinyl, isoquinolinyl, quinoxaline, methylenedioxyphenyl,imidazopyridyl, benzoxazolyl, and indolyl, substituted with halo,haloalkyl, alkoxy, cyano, amino, sulfo, substituted sulfo, substitutedsulfonyl, sulfonamide and cycloalkyl.

In some embodiments, with respect to formulae 1-3b, R¹ is selected fromquinolinyl, isoquinolinyl, quinoxaline, methylenedioxyphenyl,imidazopyridyl, benzoxazolyl, and indolyl, substituted with Me, Et, Pr,iso-Pr, Ph, Cl, F, Br, CN, OH, OMe, OEt, OPh, COPh, CO₂Me,CH₂—N-morpholino, CH₂—N-(4-Me-piperidino), NH₂, CONH₂, CF₃, CHF₂, OCF₃,OCHF₂, t-Bu, SMe, CH═CH—CO₂H, SOMe, SO₂Me, SO₂CF₃, SO₂NH₂, SO₃H, SO₃Me,cyclopropyl.

In some embodiments, with respect to formulae 1-3b, R¹ is a phenyl. Incertain embodiments, R¹ is a substituted phenyl.

In some embodiments, with respect to formulae 1-3b, R¹ is amono-substituted phenyl.

In other embodiments, with respect to formulae 1-3b, R¹ is adi-substituted phenyl.

In certain embodiments, with respect to formulae 1-3b, R¹ is asubstituted phenyl where the substituent on the phenyl is selected fromhalo, amido, alkyl, alkoxy, sulfonyl, sulfonamidyl, haloalkyl andtrihaloalkyl. In preferred embodiments, the substitution on the R¹phenyl is selected from Cl, F, CF₃, Me, OMe, SO₂R^(2′), NR^(2′)R^(2′),and SO₂NR^(2′)R^(2′). In more preferred embodiments, the substitution onthe R¹ phenyl is selected from H, Cl, Me and SO₂Me.

In certain embodiments, with respect to formulae 1-3b, R¹ is adisubstituted phenyl, and the two substitutions are selected fromsubstituted sulfonyl, halo, and alkyl.

In certain embodiments, with respect to formulae 1-3b, R¹ is adisubstituted phenyl, and one substitution is SO₂Me and the othersubstitution is Cl, Me, or CF₃.

In embodiments where with respect to formulae 1-3b, R¹ is a substitutedphenyl, one or more substitutents are on the phenyl at the 2 (ortho), 3(meta) and/or 4 (para) position relative to the carbon attached to thenitrogen atom in the fused heterocyclic scaffold in formula 1, 1a or 1b.

In some embodiments, with respect to formulae 1-3b, R¹ is a heteroaryl.

In certain embodiments, with respect to formulae 1-3b, R¹ is asubstituted pyridyl or pyrimidine group.

In some embodiments, with respect to formulae 1-3b, R¹ is a substitutedpyridyl.

In some embodiments, with respect to formulae 1-3b, R¹ is a substitutedpyrid-3-yl. In certain embodiments, the R¹ pyrid-2-yl is di-substituted.In preferred embodiments, the R¹ pyrid-3-yl is mono substituted.

In some embodiments, with respect to formulae 1-3b, R¹ is a substitutedpyrid-3-yl and the substituent on the R¹ pyrid-3-yl is selected fromhalo, amido, alkyl, alkoxy, sulfonyl, sulfonamidyl, haloalkyl andtrihaloalkyl.

In preferred embodiments, with respect to formulae 1-3b, thesubstitution on R¹ pyrid-3-yl is selected from Cl, F, CF₃, Me, OMe,SO₂R^(2′), NR^(2′)R^(2′), and SO₂NR^(2′)R^(2′). In more preferredembodiments, the substitution on R¹ pyrid-3-yl is selected from Cl, Meand SO₂Me.

In some embodiments, R¹ is selected from

wherein subscript n′ is selected from 1-5 and each of R⁵ isindependently selected from hydrogen, substituted or unsubstitutedalkyl, substituted or unsubstituted acyl, substituted or unsubstitutedacylamino, substituted or unsubstituted alkylamino, substituted orunsubstituted alkythio, substituted or unsubstituted alkoxy, aryloxy,alkoxycarbonyl, substituted alkoxycarbonyl, substituted or unsubstitutedalkylarylamino, arylalkyloxy, substituted arylalkyloxy, amino, aryl,substituted aryl, arylalkyl, sulfo, substituted sulfo, substitutedsulfonyl, substituted sulfinyl, substituted sulfanyl, azido, substitutedor unsubstituted carbamoyl, carboxyl, cyano, substituted orunsubstituted cycloalkyl, substituted or unsubstituted cycloheteroalkyl,substituted or unsubstituted dialkylamino, halo, heteroaryloxy,substituted or unsubstituted heteroaryl, substituted or unsubstitutedheteroalkyl, hydroxy, nitro, and thiol.

In certain embodiments, the subscript n′ is 1, 2 or 3.

In further embodiments, the subscript n′ is 1 or 2.

In certain embodiments, each R⁵ is H.

In certain embodiments, each R⁵ is independently alkyl or substitutedalkyl.

In certain embodiments, each R⁵ is independently Cl or F.

In certain embodiments, each R⁵ is independently alkoxy or substitutedalkoxy.

In certain embodiments, each R⁵ is independently amino or substitutedamino.

In certain embodiments, each R⁵ is independently carbamoyl.

In certain embodiments, each R⁵ is independently sulfo or substitutedsulfo.

In certain embodiments, each R⁵ is independently sulfonyl or substitutedsulfonyl.

In certain embodiments, each R⁵ is independently aminosulfonyl orsubstituted aminosulfonyl.

In certain embodiments, each R⁵ is independently SO₂NH₂.

In certain embodiments, each R⁵ is independently selected from Me, Et,Pr, iso-Pr, Ph, Cl, F, Br, CN, OH, OMe, OEt, OPh, COPh, CO₂Me,CH₂—N-morpholino, CH₂—N-(4-Me-piperidino), NH₂, CONH₂, CF₃, CHF₂, OCF₃,OCHF₂, t-Bu, SMe, CH═CH—CO₂H, SOMe, SO₂Me, SO₂CF₃, SO₂NH₂, SO₃H, SO₃Me,cyclopropyl, triazolyl, morpholinyl, and pyridyl.

In certain embodiments, the subscript n′ is 1 and R⁵ is selected fromMe, Cl, F, OMe, and CF₃.

In some embodiments, with respect to formulae 1-3b, R¹ is

and R⁵ is halo or alkyl. In one embodiment, R⁵ is Cl or Me.

With regard to formula 1, in certain embodiments, a compound isaccording to formula 4a, 4b, or 4c:

wherein R² is as described for formulae 3a-3b and R⁵ is as describedabove. In certain embodiments, when R² is other than H, the compoundsaccording to formula 4a, 4b, or 4c are enantiomerically pure. In certainembodiments, pharmaceutical compositions are provided comprisingenantiomerically pure compounds according to formula 4a, 4b, or 4c. Incertain embodiments, methods of treatment are provided that compriseadministering an enantiomerically pure compound according to formula 4a,4b, or 4c or a pharmaceutical composition comprising an enantiomericallypure compound according to formula 4a, 4b, or 4c.

In certain embodiments, with respect to formulae 4a-4c, R⁵ is H.

In certain embodiments, with respect to formulae 4a-4c, R⁵ is Me, Et,Pr, iso-Pr, Ph, Cl, F, CN, OH, OMe, OEt, OPh, CF₃, CHF₂, OCF₃, OCHF₂,t-Bu, SO₂Me, SO₂CF₃, and SO₃Me.

In certain embodiments, with respect to formulae 4a-4c, R⁵ is Cl, F, Me,CF₃, or OMe.

In certain embodiments, with respect to formulae 1-4c, R² is selectedfrom H, Me, Et, n-Pr, t-Bu, CF₃, CH₂OH, CH₂CH₂OH, CH₂CH₂OAc,CH₂(CH₂)₂OH, CH₂CH₂NHMe, CH₂NMe₂, CH₂CH₂NMe₂, CH₂CONH₂, CH₂CONMe₂,CH₂COOH, CH₂CH₂COOH, CH₂(CH₂)₂COOH, CH₂OMe, and CH₂CH₂OMe.

In further embodiments, with respect to formulae 1-4c, R² is selectedfrom CH₂NR^(2′)R^(2″), CH₂CH₂NR^(2′)R^(2″), CH₂CH₂CH₂NR^(2′)R^(2″) andwherein R^(2′) and R^(2″) can join together to form a heterocyclic ring.

In certain embodiments, with respect to formulae 1-4c, R² is selectedfrom cyclopropyl, cyclobutyl or cyclohexyl.

In particular embodiments, with respect to formulae 1-4c, R² is Me orEt.

In more particular embodiments, with respect to formulae 1-4c, R² isCH₂OH, or CH₂CH₂OH.

In certain embodiments, with respect to formulae 1-4c, R³ is H.

In certain embodiments, with respect to formulae 1-4c, R³ is selectedfrom cyclopropyl, cyclobutyl or cyclohexyl.

In particular embodiments, with respect to formulae 1-4c, R³ is Me, Cl,F, or CF₃.

In more particular embodiments, with respect to formulae 1-4c, R³ is Cl.

In more particular embodiments, with respect to formula 1, the compoundis according to formula 5a, 5b, or 5c:

and wherein R² is as described for formula 1; and R⁵ as described above.

In certain embodiments, with regard to formula 5a, 5b, or 5c, R² is H.

In certain embodiments, with regard to formula 5a, 5b, or 5c, R² is Me,Et or CH₂OH. In particular embodiments, R² is Me, CH₂OH, or CH₂CH₂OH.

In certain embodiments, with regard to formula 5a, 5b, or 5c, R⁵ is H,Cl, F, Me, CF₃, or OMe. In particular embodiments, R⁵ is Cl, F or CF₃,or OMe.

In certain embodiments, with respect to formulae 4a or 5a, the

group is replaced with

and wherein R⁵ is H, Cl, Me or CF₃.

In certain embodiments, with respect to formulae 4a or 5a, the

group is replaced with

In certain embodiments, with respect to formulae 4a or 5a, the

group is replaced with

and wherein R⁵ is H, Cl, Me, OMe, or CF₃.

In certain embodiments, with respect to formulae 4a or 5a, the

group is replaced with

In certain embodiments, with respect to formulae 4a or 5a, the

group is replaced with

In certain embodiments, with respect to formulae 4a or 5a, the

group is replaced with

In certain embodiments, with respect to formulae 4a or 5a, the

group is replaced with

and wherein R⁵ is H, Cl, Me, OMe, or CF₃.

In certain embodiments, with respect to formulae 1-5c, R² is Me.

In certain embodiments, with respect to formulae 1-5c, R² is Et.

In certain embodiments, with respect to formulae 1-5c, R² is CH₂OH.

In certain embodiments, with respect to formulae 1-5c, R² is CH₂CH₂OH.

In certain embodiments, with respect to formulae 1-5c, R⁵ is H.

In certain embodiments, with respect to formulae 1-5c, R⁵ is Cl.

In certain embodiments, with respect to formulae 1-5c, R⁵ is CF₃.

In certain embodiments, with respect to formulae 1-5c, R⁵ is Me.

In certain embodiments, with respect to formulae 1-5c, R⁵ is OMe.

In certain embodiments, when R³, R⁴ or R⁵ is alkyl; the alkyl group isC₁-C₈alkyl. In another embodiment, the alkyl group is C₁-C₆alkyl. In afurther embodiment, the alkyl group is C₁-C₄alkyl.

In one embodiment, the alkyl group is optionally substituted by one ormore groups (such as 1 to 3 substituents, in particular one substituentgroup, which substituent group may be independently selected from halo,cyano, nitro, trifluoromethyl, trifluoromethoxy, azido, —NR¹⁰SO₂R⁹,—SO₂NR⁹R¹⁰, —C(O)R⁹, —C(O)OR⁹, —OC(O)R⁹, —NR¹⁰C(O)R⁹, —C(O)NR⁹R¹⁰,—NR⁹R¹⁰, —(CR¹⁰R¹¹)_(m)OR¹⁰ and wherein m is an integer from 1 to 5.

In one embodiment, each R⁹ is independently selected from H, C₁-C₈alkyl,—(CH₂)_(t)(C₆-C₁₀ aryl), —(CH₂)_(t)(C₅-C₁₀ heteroaryl),—(CH₂)_(t)(C₃-C₁₀ cycloalkyl), and —(CH₂)_(t)(C₅-C₁₀ heterocycloalkyl),wherein t is an integer from 0 to 4.

In one embodiment, each R⁹ is as described above, and any aryl,heteroaryl, cycloalkyl or heterocycloalkyl groups present, maythemselves be substituted by C₁-C₄alkyl, halo, C₁-C₄alkoxy,C₁₋₄haloalkyl, C₁-C₄hydroxyalkyl, or C₁-C₄haloalkoxy or hydroxy.

In one embodiment, each R⁹ is as described above, and each of R¹⁰ andR¹¹ independently represents H or C₁-C₆alkyl.

In one embodiment, each R⁹ is as described above and each of R¹² and R¹³independently represents H or C₁-C₄alkyl.

In one embodiment, each of R¹⁰ and R¹¹ independently represents H orC₁-C₆alkyl.

In one embodiment, each R⁹ is other than H.

In certain embodiments, when R³, R⁴ or R⁵ is alkoxy; the alkoxy group is—OR⁹; and R⁹ is as described in the above embodiments; provided that R⁹is other than H.

In certain embodiments, when R³, R⁴ or R⁵ is acyl; the acyl group is—C(O)R⁹; and R⁹ is as described in the above embodiments.

In certain embodiments, when R³, R⁴ or R⁵ is alkoxycarbonyl; thealkoxycarbonyl group is —C(O)OR⁹; and R⁹ is as described in the aboveembodiments; provided that R⁹ is other than H.

In certain embodiments, when R³, R⁴ or R⁵ is acylamino; the acylaminogroup is —NR¹⁰C(O)R⁹; and R⁹ and R¹⁰ are as described in the aboveembodiments; provided that R⁹ is other than H.

In certain embodiments, when R³, R⁴ or R⁵ is acyloxy; the acyloxy groupis —OC(O)R⁹; and R⁹ is as described in the above embodiments; providedthat R⁹ is other than H.

In certain embodiments, when R³, R⁴ or R⁵ is sulfo; the sulfo group is—SO₃R⁹; and R⁹ is as described in the above embodiments.

In certain embodiments, when R³, R⁴ or R⁵ is sulfonyl; the sulfonylgroup is —SO₂R⁹; and R⁹ is as described in the above embodiments;provided that R⁹ is other than H.

In certain embodiments, when R³, R⁴ or R⁵ is sulfinyl; the sulfinylgroup is —SOR⁹; and R⁹ is as described in the above embodiments;provided that R⁹ is other than H.

In certain embodiments, when R³, R⁴ or R⁵ is aminosulfonyl; theaminosulfonyl group is —SO₂NR⁹R¹⁰; and R⁹ and R¹⁰ are as described inthe above embodiments.

In certain embodiments, when R³, R⁴ or R⁵ is amino; the amino group is—NR⁹R¹⁰; and R⁹ and R¹⁰ are as described in the above embodiments.

In certain embodiments, when R³, R⁴ or R⁵ is carbamoyl; the carbamoylgroup is —CO₂NR⁹R¹⁰; and R⁹ and R¹⁰ are as described in the aboveembodiments.

In certain embodiments, when R³, R⁴ or R⁵ is alkylthio; the alkylthiogroup is —SR⁹; and R⁹ is as described in the above embodiments; providedthat R⁹ is other than H.

With regard to formula 1, in certain embodiments, the compound isselected from the group consisting of

-   5-Methyl-2-{4-[(6-trifluoromethyl-pyridin-3-ylmethyl)-amino]-7,8-dihydro-5H-pyrido[4,3-d]pyrimidin-6-yl}-benzonitrile;-   5-Bromo-2-{4-[(6-trifluoromethyl-pyridin-3-ylmethyl)-amino]-7,8-dihydro-5H-pyrido[4,3-d]pyrimidin-6-yl}-benzonitrile;-   5-Cyclopropyl-2-{4-[(6-trifluoromethyl-pyridin-3-ylmethyl)-amino]-7,8-dihydro-5H-pyrido[4,3-d]pyrimidin-6-yl}-benzonitrile;-   5-Chloro-2-{4-[(6-trifluoromethyl-pyridin-3-ylmethyl)-amino]-7,8-dihydro-5H-pyrido[4,3-d]pyrimidin-6-yl}-benzonitrile;-   5-Trifluoromethyl-2-{4-[(6-trifluoromethyl-pyridin-3-ylmethyl)-amino]-7,8-dihydro-5H-pyrido[4,3-d]pyrimidin-6-yl}-benzonitrile;-   5-Bromo-2-{4-[(R)-1-(6-trifluoromethyl-pyridin-3-yl)-ethylamino]-7,8-dihydro-5H-pyrido[4,3-d]pyrimidin-6-yl}-benzonitrile;-   5-Methyl-2-{4-[(R)-1-(6-trifluoromethyl-pyridin-3-yl)-ethylamino]-7,8-dihydro-5H-pyrido[4,3-d]pyrimidin-6-yl}-benzonitrile;-   5-Chloro-2-{4-[(R)-1-(6-trifluoromethyl-pyridin-3-yl)-ethylamino]-7,8-dihydro-5H-pyrido[4,3-d]pyrimidin-6-yl}-benzonitrile;-   5-Fluoro-2-{4-[(6-trifluoromethyl-pyridin-3-ylmethyl)-amino]-7,8-dihydro-5H-pyrido[4,3-d]pyrimidin-6-yl}-benzonitrile;-   2-{4-[(6-Trifluoromethyl-pyridin-3-ylmethyl)-amino]-7,8-dihydro-5H-pyrido[4,3-d]pyrimidin-6-yl}-benzonitrile;-   5-Chloro-2-{4-[(2-methyl-6-trifluoromethyl-pyridin-3-ylmethyl)-amino]-7,8-dihydro-5H-pyrido[4,3-d]pyrimidin-6-yl}-benzonitrile;-   5-Chloro-2-{4-[(6-dimethylamino-pyridin-3-ylmethyl)-amino]-7,8-dihydro-5H-pyrido[4,3-d]pyrimidin-6-yl}-benzonitrile;-   5-Chloro-2-{4-[(6-methoxy-pyridin-3-ylmethyl)-amino]-7,8-dihydro-5H-pyrido[4,3-d]pyrimidin-6-yl}-benzonitrile;-   5-Bromo-2-{4-[(6-methoxy-pyridin-3-ylmethyl)-amino]-7,8-dihydro-5H-pyrido[4,3-d]pyrimidin-6-yl}-benzonitrile;-   2-{4-[(6-Methoxy-pyridin-3-ylmethyl)-amino]-7,8-dihydro-5H-pyrido[4,3-d]pyrimidin-6-yl}-5-methyl-benzonitrile;-   5-Chloro-2-{4-[(3-chloro-5-trifluoromethyl-pyridin-2-ylmethyl)-amino]-7,8-dihydro-5H-pyrido[4,3-d]pyrimidin-6-yl}-benzonitrile;-   5-Chloro-2-{4-[(5-trifluoromethyl-pyridin-2-ylmethyl)-amino]-7,8-dihydro-5H-pyrido[4,3-d]pyrimidin-6-yl}-benzonitrile;-   (R)-3-[6-(4-Chloro-2-cyano-phenyl)-5,6,7,8-tetrahydro-pyrido[4,3-d]pyrimidin-4-ylamino]-3-(6-methoxy-pyridin-3-yl)-propionic    acid tert-butyl ester;-   (R)-3-[6-(4-Chloro-2-cyano-phenyl)-5,6,7,8-tetrahydro-pyrido[4,3-d]pyrimidin-4-ylamino]-3-(6-methoxy-pyridin-3-yl)-propionic    acid;-   5-Chloro-2-{4-[(R)-3-hydroxy-1-(6-trifluoromethyl-pyridin-3-yl)-propylamino]-7,8-dihydro-5H-pyrido[4,3-d]pyrimidin-6-yl}-benzonitrile;-   2-{4-[(R)-3-Hydroxy-1-(6-methyl-pyridin-3-yl)-propylamino]-7,8-dihydro-5H-pyrido[4,3-d]pyrimidin-6-yl}-5-methyl-benzonitrile;-   2-{4-[(R)-1-(6-Difluoromethyl-pyridin-3-yl)-3-hydroxy-propylamino]-7,8-dihydro-5H-pyrido[4,3-d]pyrimidin-6-yl}-5-methyl-benzonitrile;-   2-{4-[(S)-2-Hydroxy-1-(6-methoxy-pyridin-3-yl)-ethylamino]-7,8-dihydro-5H-pyrido[4,3-d]pyrimidin-6-yl}-5-methyl-benzonitrile;-   2-{4-[(R)-3-Hydroxy-1-(6-methoxy-pyridin-3-yl)-propylamino]-7,8-dihydro-5H-pyrido[4,3-d]pyrimidin-6-yl}-5-methyl-benzonitrile;-   2-{4-[3-Hydroxy-1-(6-trifluoromethyl-pyridin-3-yl)-propylamino]-7,8-dihydro-5H-pyrido[4,3-d]pyrimidin-6-yl}-5-methyl-benzonitrile;-   2-{4-[(S)-2-Methoxy-1-(6-methoxy-pyridin-3-yl)-ethylamino]-7,8-dihydro-5H-pyrido[4,3-d]pyrimidin-6-yl}-5-methyl-benzonitrile;-   2-{4-[(6-Chloro-pyridin-3-ylmethyl)-amino]-7,8-dihydro-5H-pyrido[4,3-d]pyrimidin-6-yl}-5-methyl-benzonitrile;-   2-{-4-[(5-Chloro-pyridin-2-ylmethyl)-amino]-7,8-dihydro-5,1-pyrido[4,3-d]pyrimidin-6-yl}-5-methyl-benzonitrile;-   5-Methyl-2-{4-[(pyridin-2-ylmethyl)-amino]-7,8-dihydro-5H-pyrido[4,3-d]pyrimidin-6-yl}-benzonitrile;-   2-{4-[(5-Cyclopropyl-pyridin-2-ylmethyl)-amino]-7,8-dihydro-5H-pyrido[4,3-d]pyrimidin-6-yl}-5-methyl-benzonitrile;-   2-{4-[(4-Amino-2-methyl-pyrimidin-5-ylmethyl)-amino]-7,8-dihydro-5H-pyrido[4,3-d]pyrimidin-6-yl}-5-methyl-benzonitrile;-   2-{-4-[(3,5-Dichloro-pyridin-2-ylmethyl)-amino]-7,8-dihydro-5H-pyrido[4,3-d]pyrimidin-6-yl}-5-methyl-benzonitrile;-   2-{4-[(6-Ethyl-pyridin-3-ylmethyl)-amino]-7,8-dihydro-5H-pyrido[4,3-d]pyrimidin-6-yl}-5-methyl-benzonitrile;-   5-Chloro-2-{4-[(R)-3-hydroxy-1-(6-methoxy-pyridin-3-yl)-propylamino]-7,8-dihydro-5H-pyrido[4,3-d]pyrimidin-6-yl}-benzonitrile;-   5-Chloro-2-{4-[(S)-2-hydroxy-1-(6-methoxy-pyridin-3-yl)-ethylamino]-7,8-dihydro-5H-pyrido[4,3-d]pyrimidin-6-yl}-benzonitrile;-   2-[4-(3-Cyano-benzylamino)-7,8-dihydro-5H-pyrido[4,3-d]pyrimidin-6-yl]-5-methyl-benzonitrile;-   2-{4-[(Imidazo[1,2-a]pyridin-7-ylmethyl)-amino]-7,8-dihydro-5H-pyrido[4,3-d]pyrimidin-6-yl}-5-methyl-benzonitrile;-   2-[4-[(Benzooxazol-5-ylmethyl)-amino]-7,8-dihydro-5H-pyrido[4,3-d]pyrimidin-6-yl]-5-methyl-benzonitrile;-   5-Methyl-2-{4-[(2-methyl-pyrimidin-5-ylmethyl)-amino]-7,8-dihydro-5H-pyrido[4,3-d]pyrimidin-6-yl}-benzonitrile;-   5-Methyl-2-{4-(4-methyl-3-[1,2,4]triazol-1-yl-benzylamino)-7,8-dihydro-5H-pyrido[4,3-d]pyrimidin-6-yl}-benzonitrile;-   (R)-3-[6-(2-Cyano-4-methyl-phenyl)-5,6,7,8-tetrahydro-pyrido[4,3-d]pyrimidin-4-ylamino]-3-(6-methoxy-pyridin-3-yl)-propionic    acid;-   (R)-3-[6-(2-Cyano-4-methyl-phenyl)-5,6,7,8-tetrahydro-pyrido[4,3-d]pyrimidin-4-ylamino]-3-(6-methoxy-pyridin-3-yl)-propionamide;-   (R)-3-[6-(2-Cyano-4-methyl-phenyl)-5,6,7,8-tetrahydro-pyrido[4,3-d]pyrimidin-4-ylamino]-3-(6-methoxy-pyridin-3-yl)-N,N-dimethyl-propionamide;-   5-Chloro-2-{4-[(imidazo[1,2-a]pyridin-7-ylmethyl)-amino]-7,8-dihydro-5H-pyrido[4,3-d]pyrimidin-6-yl}-benzonitrile;-   5-Chloro-2-{4-[(2-methyl-pyrimidin-5-ylmethyl)-amino]-7,8-dihydro-5H-pyrido[4,3-d]pyrimidin-6-yl}-benzonitrile;-   2-{4-[(S)-2-Hydroxy-1-(6-trifluoromethyl-pyridin-3-yl)-ethylamino]-7,8-dihydro-5H-pyrido[4,3-d]pyrimidin-6-yl}-5-methyl-benzonitrile;-   5-Chloro-2-{4-[(S)-2-hydroxy-1-(6-trifluoromethyl-pyridin-3-yl)-ethylamino]-7,8-dihydro-5H-pyrido[4,3-d]pyrimidin-6-yl}-benzonitrile;-   2-[4-(3-Fluoro-4-methyl-benzylamino)-7,8-dihydro-5H-pyrido[4,3-d]pyrimidin-6-yl]-5-methyl-benzonitrile;-   5-Methyl-2-[4-(4-methyl-3-methylsulfanyl-benzylamino)-7,8-dihydro-5H-pyrido[4,3-d]pyrimidin-6-yl]-benzonitrile;-   2-[4-(4-Chloro-3-[1,2,4]triazol-4-yl-benzylamino)-7,8-dihydro-5H-pyrido[4,3-d]pyrimidin-6-yl]-5-methyl-benzonitrile;-   5-Chloro-2-[4-(3-[1,2,4]triazol-4-yl-benzylamino)-7,8-dihydro-5H-pyrido[4,3-d]pyrimidin-6-yl]-benzonitrile;-   5-Chloro-2-[4-(4-chloro-3-[1,2,4]triazol-4-yl-benzylamino)-7,8-dihydro-5H-pyrido[4,3-d]pyrimidin-6-yl]-benzonitrile;-   5-Methyl-2-[4-(3-[1,2,4]triazol-4-yl-benzylamino)-7,8-dihydro-5H-pyrido[4,3-d]pyrimidin-6-yl]-benzonitrile;-   2-{4-[(4-Amino-2-methoxy-pyrimidin-5-ylmethyl)-amino]-7,8-dihydro-5H-pyrido[4,3-d]pyrimidin-6-yl}-5-methyl-benzonitrile;-   2-[4-(3-Iodo-4-methyl-benzylamino)-7,8-dihydro-5H-pyrido[4,3-d]pyrimidin-6-yl]-5-methyl-benzonitrile;-   5-Chloro-2-{4-[(R)-1-(2-methoxy-pyrimidin-5-yl)-ethylamino]-7,8-dihydro-5H-pyrido[4,3-d]pyrimidin-6-yl}-benzonitrile;-   2-{4-[(R)-1-(2-Methoxy-pyrimidin-5-yl)-ethylamino]-7,8-dihydro-5H-pyrido[4,3-d]pyrimidin-6-yl}-5-methyl-benzonitrile;-   2-{4-(3-Methanesulfonyl-4-methyl-benzylamino)-7,8-dihydro-5H-pyrido[4,3-d]pyrimidin-6-yl}-5-methyl-benzonitrile;-   2-{4-[(S)-2-Hydroxy-1-(2-methoxy-pyrimidin-5-yl)-ethylamino]-7,8-dihydro-5H-pyrido[4,3-d]pyrimidin-6-yl}-5-methyl-benzonitrile;-   2-{4-[(2-Isopropyl-pyrimidin-5-ylmethyl)-amino]-7,8-dihydro-5H-pyrido[4,3-d]pyrimidin-6-yl}-5-methyl-benzonitrile;-   5-Chloro-2-{4-[(R)-1-(6-difluoromethyl-pyridin-3-yl)-3-hydroxy-propylamino]-7,8-dihydro-5H-pyrido[4,3-d]pyrimidin-6-yl}-benzonitrile;-   5-Methyl-2-[4-(4-methyl-3-morpholin-4-yl-benzylamino)-7,8-dihydro-5H-pyrido[4,3-d]pyrimidin-6-yl]-benzonitrile;-   2-{4-[(R)-3-Hydroxy-1-(6-trifluoromethyl-pyridin-3-yl)-propylamino]-7,8-dihydro-5H-pyrido[4,3-d]pyrimidin-6-yl}-5-methyl-benzonitrile;-   2-{4-[(S)-3-Hydroxy-1-(6-trifluoromethyl-pyridin-3-yl)-propylamino]-7,8-dihydro-5H-pyrido[4,3-d]pyrimidin-6-yl}-5-methyl-benzonitrile;-   5-Methyl-2-{4-[(R)-1-(2-methyl-pyrimidin-5-yl)-ethylamino]-7,8-dihydro-5H-pyrido[4,3-d]pyrimidin-6-yl}-benzonitrile;-   5-Methyl-2-{4-[(S)-1-(2-methyl-pyrimidin-5-yl)-ethylamino]-7,8-dihydro-5H-pyrido[4,3-d]pyrimidin-6-yl}-benzonitrile;-   2-{4-[(2-Methoxy-pyrimidin-5-ylmethyl)-amino]-7,8-dihydro-5H-pyrido[4,3-d]pyrimidin-6-yl}-5-methyl-benzonitrile;-   5-Chloro-2-{4-[(2-methoxy-pyrimidin-5-ylmethyl)-amino]-7,8-dihydro-5H-pyrido[4,3-d]pyrimidin-6-yl}-benzonitrile;-   2-{4-[(S)-1-(6-Difluoromethyl-pyridin-3-yl)-2-hydroxy-ethylamino]-7,8-dihydro-5H-pyrido[4,3-d]pyrimidin-6-yl}-5-methyl-benzonitrile;-   2-[4-(4-Chloro-3-methanesulfonyl-benzylamino)-7,8-dihydro-5H-pyrido[4,3-d]pyrimidin-6-yl]-5-methyl-benzonitrile;-   5-Chloro-2-[4-[(S)-1-(6-difluoromethyl-pyridin-3-yl)-2-hydroxy-ethylamino]-7,8-dihydro-5H-pyrido[4,3-d]pyrimidin-6-yl]-benzonitrile;-   5-Chloro-2-{4-[(S)-2-hydroxy-1-(2-methyl-pyrimidin-5-yl)-ethylamino]-7,8-dihydro-5H-pyrido[4,3-d]pyrimidin-6-yl}-benzonitrile;-   2-{4-[(S)-2-Hydroxy-1-(2-methyl-pyrimidin-5-yl)-ethylamino]-7,8-dihydro-5H-pyrido[4,3-d]pyrimidin-6-yl}-5-methyl-benzonitrile;-   5-Chloro-2-{4-[(R)-1-(2-methyl-pyrimidin-5-yl)-ethylamino]-7,8-dihydro-5H-pyrido[4,3-d]pyrimidin-6-yl}-benzonitrile;-   5-Chloro-2-[4-(3-methanesulfonyl-4-methyl-benzylamino)-7,8-dihydro-5H-pyrido[4,3-d]pyrimidin-6-yl]-benzonitrile;-   Acetic acid    (R)-3-[6-(2-cyano-4-methyl-phenyl)-5,6,7,8-tetrahydro-pyrido[4,3-d]pyrimidin-4-ylamino]-3-(6-trifluoromethyl-pyridin-3-yl)-propyl    ester;-   5-Chloro-2-{4-[(S)-2-hydroxy-1-(2-methoxy-pyrimidin-5-yl)-ethylamino]-7,8-dihydro-5H-pyrido[4,3-d]pyrimidin-6-yl}-benzonitrile;-   5-Methyl-2-{4-[(quinoxalin-6-ylmethyl)-amino]-7,8-dihydro-5H-pyrido[4,3-d]pyrimidin-6-yl}-benzonitrile;-   5-Methyl-2-{4-[(quinolin-2-ylmethyl)-amino]-7,8-dihydro-5H-pyrido[4,3-d]pyrimidin-6-yl}-benzonitrile;-   2-{4-[(1H-Indol-6-ylmethyl)-amino]-7,8-dihydro-5H-pyrido[4,3-d]pyrimidin-6-yl}-5-methyl-benzonitrile;-   2-{4-[(Benzo[1,3]dioxol-5-ylmethyl)-amino]-7,8-dihydro-5H-pyrido[4,3-d]pyrimidin-6-yl}-5-methyl-benzonitrile;-   2-[4-(1-Benzo[1,3]dioxol-5-yl-ethylamino)-7,8-dihydro-5H-pyrido[4,3-d]pyrimidin-6-yl]-5-methyl-benzonitrile;-   5-Chloro-2-{4-[(quinoxalin-6-ylmethyl)-amino]-7,8-dihydro-5H-pyrido[4,3-d]pyrimidin-6-yl}-benzonitrile;-   5-Methyl-2-[4-(1-pyrazin-2-yl-ethylamino)-7,8-dihydro-5H-pyrido[4,3-d]pyrimidin-6-yl]-benzonitrile;-   5-Methyl-2-[4-(1-quinoxalin-6-yl-ethylamino)-7,8-dihydro-5H-pyrido[4,3-d]pyrimidin-6-yl]-benzonitrile;-   2-{4-[(S)-1-(2-Methoxy-pyrimidin-5-yl)-ethylamino]-7,8-dihydro-5H-pyrido[4,3-d]pyrimidin-6-yl}-5-methyl-benzonitrile;-   2-{4-[1-(4-Chloro-3-methanesulfonyl-phenyl)-ethylamino]-7,8-dihydro-5H-pyrido[4,3-d]pyrimidin-6-yl}-5-methyl-benzonitrile;-   2-[4-((R)-1-Benzo[1,3]dioxol-5-yl-ethylamino)-7,8-dihydro-5H-pyrido[4,3-d]pyrimidin-6-yl]-5-methyl-benzonitrile;-   2-[4-((S)-1-Benzo[1,3]dioxol-5-yl-ethylamino)-7,8-dihydro-5H-pyrido[4,3-d]pyrimidin-6-yl]-5-methyl-benzonitrile;-   2-{4-[1-(3-M    ethanesulfonyl-4-methyl-phenyl)-ethylamino]-7,8-dihydro-5H-pyrido[4,3-d]pyrimidin-6-yl}-5-methyl-benzonitrile;-   5-Methyl-2-{4-[(quinolin-7-ylmethyl)-amino]-7,8-dihydro-5H-pyrido[4,3-d]pyrimidin-6-yl}-benzonitrile;-   2-{4-[(R)-1-(4-Chloro-3-methanesulfonyl-phenyl)-ethylamino]-7,8-dihydro-5H-pyrido[4,3-d]pyrimidin-6-yl}-5-methyl-benzonitrile;-   2-{4-[(S)-1-(4-Chloro-3-methanesulfonyl-phenyl)-ethylamino]-7,8-dihydro-5H-pyrido[4,3-d]pyrimidin-6-yl}-5-methyl-benzonitrile;-   5-Methyl-2-[4-((R)-1-quinoxalin-6-yl-ethylamino)-7,8-dihydro-5H-pyrido[4,3-d]pyrimidin-6-yl]-benzonitrile;    and-   5-Methyl-2-[4-((S)-1-quinoxalin-6-yl-ethylamino)-7,8-dihydro-5H-pyrido[4,3-d]pyrimidin-6-yl]-benzonitrile;

Additional embodiments within the scope provided herein are set forth innon-limiting fashion elsewhere herein and in the examples. It should beunderstood that these examples are for illustrative purposes only andare not to be construed as limiting in any manner.

In certain aspects, provided herein are prodrugs and derivatives of thecompounds according to the formulae above. Prodrugs are derivatives ofthe compounds provided herein, which have metabolically cleavable groupsand become by solvolysis or under physiological conditions the compoundsprovided herein, which are pharmaceutically active, in vivo. Suchexamples include, but are not limited to, choline ester derivatives andthe like, N-alkylmorpholine esters and the like.

Certain compounds provided herein have activity in both their acid andacid derivative forms, but the acid sensitive form often offersadvantages of solubility, tissue compatibility, or delayed release inthe mammalian organism (see, Bundgard, H., Design of Prodrugs, pp. 7-9,21-24, Elsevier, Amsterdam 1985). Prodrugs include acid derivatives wellknow to practitioners of the art, such as, for example, esters preparedby reaction of the parent acid with a suitable alcohol, or amidesprepared by reaction of the parent acid compound with a substituted orunsubstituted amine, or acid anhydrides, or mixed anhydrides. Simplealiphatic or aromatic esters, amides and anhydrides derived from acidicgroups pendant on the compounds provided herein are preferred prodrugs.In some cases it is desirable to prepare double ester type prodrugs suchas (acyloxy)alkyl esters or ((alkoxycarbonyl)oxy)alkylesters. Preferredare the C₁ to C₈ alkyl, C₂-C₈ alkenyl, aryl, C₇-C₁₂ substituted aryl,and C₇-C₁₂ arylalkyl esters of the compounds provided herein.

Pharmaceutical Compositions

When employed as pharmaceuticals, the fused heterocyclic compoundsprovided herein are typically administered in the form of apharmaceutical composition. Such compositions can be prepared in amanner well known in the pharmaceutical art and comprise at least oneactive compound.

Generally, the compounds provided herein are administered in atherapeutically effective amount. The amount of the compound actuallyadministered will typically be determined by a physician, in the lightof the relevant circumstances, including the condition to be treated,the chosen route of administration, the actual compound-administered,the age, weight, and response of the individual patient, the severity ofthe patient's symptoms, and the like.

The pharmaceutical compositions provided herein can be administered by avariety of routes including oral, rectal, transdermal, subcutaneous,intravenous, intramuscular, and intranasal. Depending on the intendedroute of delivery, the compounds provided herein are preferablyformulated as either injectable or oral compositions or as salves, aslotions or as patches all for transdermal administration.

The compositions for oral administration can take the form of bulkliquid solutions or suspensions, or bulk powders. More commonly,however, the compositions are presented in unit dosage forms tofacilitate accurate dosing. The term “unit dosage forms” refers tophysically discrete units suitable as unitary dosages for human subjectsand other mammals, each unit containing a predetermined quantity ofactive material calculated to produce the desired therapeutic effect, inassociation with a suitable pharmaceutical excipient. Typical unitdosage forms include prefilled, premeasured ampules or syringes of theliquid compositions or pills, tablets, capsules or the like in the caseof solid compositions. In such compositions, the furansulfonic acidcompound is usually a minor component (from about 0.1 to about 50% byweight or preferably from about 1 to about 40% by weight) with theremainder being various vehicles or carriers and processing aids helpfulfor forming the desired dosing form.

Liquid forms suitable for oral administration may include a suitableaqueous or nonaqueous vehicle with buffers, suspending and dispensingagents, colorants, flavors and the like. Solid forms may include, forexample, any of the following ingredients, or compounds of a similarnature: a binder such as microcrystalline cellulose, gum tragacanth orgelatin; an excipient such as starch or lactose, a disintegrating agentsuch as alginic acid, Primogel, or corn starch; a lubricant such asmagnesium stearate; a glidant such as colloidal silicon dioxide; asweetening agent such as sucrose or saccharin; or a flavoring agent suchas peppermint, methyl salicylate, or orange flavoring.

Injectable compositions are typically based upon injectable sterilesaline or phosphate-buffered saline or other injectable carriers knownin the art. As before, the active compound in such compositions istypically a minor component, often being from about 0.05 to 10% byweight with the remainder being the injectable carrier and the like.

Transdermal compositions are typically formulated as a topical ointmentor cream containing the active ingredient(s), generally in an amountranging from about 0.01 to about 20% by weight, preferably from about0.1 to about 20% by weight, preferably from about 0.1 to about 10% byweight, and more preferably from about 0.5 to about 15% by weight. Whenformulated as a ointment, the active ingredients will typically becombined with either a paraffinic or a water-miscible ointment base.Alternatively, the active ingredients may be formulated in a cream with,for example an oil-in-water cream base. Such transdermal formulationsare well-known in the art and generally include additional ingredientsto enhance the dermal penetration of stability of the active ingredientsor the formulation. All such known transdermal formulations andingredients are included within the scope provided herein.

The compounds provided herein can also be administered by a transdermaldevice. Accordingly, transdermal administration can be accomplishedusing a patch either of the reservoir or porous membrane type, or of asolid matrix variety.

The above-described components for orally administrable, injectable ortopically administrable compositions are merely representative. Othermaterials as well as processing techniques and the like are set forth inPart 8 of Remington's Pharmaceutical Sciences, 17th edition, 1985, MackPublishing Company, Easton, Pa., which is incorporated herein byreference.

The above-described components for orally administrable, injectable ortopically administrable compositions are merely representative. Othermaterials as well as processing techniques and the like are set forth inPart 8 of Remington's The Science and Practice of Pharmacy, 21stedition, 2005, Publisher: Lippincott Williams & Wilkins, which isincorporated herein by reference.

The compounds of this invention can also be administered in sustainedrelease forms or from sustained release drug delivery systems. Adescription of representative sustained release materials can be foundin Remington's Pharmaceutical Sciences.

The following formulation examples illustrate representativepharmaceutical compositions of this invention. The present invention,however, is not limited to the following pharmaceutical compositions.

Formulation 1 Tablets

A compound of the invention is admixed as a dry powder with a drygelatin binder in an approximate 1:2 weight ratio. A minor amount ofmagnesium stearate is added as a lubricant. The mixture is formed into240-270 mg tablets (80-90 mg of active amide compound per tablet) in atablet press.

Formulation 2 Capsules

A compound of the invention is admixed as a dry powder with a starchdiluent in an approximate 1:1 weight ratio. The mixture is filled into250 mg capsules (125 mg of active amide compound per capsule).

Formulation 3 Liquid

A compound of the invention (125 mg), sucrose (1.75 g) and xanthan gum(4 mg) are blended, passed through a No. 10 mesh U.S. sieve, and thenmixed with a previously made solution of microcrystalline cellulose andsodium carboxymethyl cellulose (11.89, 50 mg) in water. Sodium benzoate(10 mg), flavor, and color are diluted with water and added withstirring. Sufficient water is then added to produce a total volume of 5mL.

Formulation 4 Tablets

A compound of the invention is admixed as a dry powder with a drygelatin binder in an approximate 1:2 weight ratio. A minor amount ofmagnesium stearate is added as a lubricant. The mixture is formed into450-900 mg tablets (150-300 mg of active amide compound) in a tabletpress.

Formulation 5 Injection

A compound of the invention is dissolved or suspended in a bufferedsterile saline injectable aqueous medium to a concentration ofapproximately 5 mg/ml.

Formulation 6 Topical

Stearyl alcohol (250 g) and a white petrolatum (250 g) are melted atabout 75° C. and then a mixture of a compound of the invention (50 g)methylparaben (0.25 g), propylparaben (0.15 g), sodium lauryl sulfate(10 g), and propylene glycol (120 g) dissolved in water (about 370 g) isadded and the resulting mixture is stirred until it congeals.

Methods of Treatment

The present fused heterocyclic compounds are used as therapeutic agentsfor the treatment of conditions in mammals. Accordingly, the compoundsand pharmaceutical compositions of this invention find use astherapeutics for preventing and/or treating neurodegenerative,autoimmune and inflammatory conditions in mammals including humans.Thus, and as stated earlier, the present invention includes within itsscope, and extends to, the recited methods of treatment, as well as tothe compounds for such methods, and for the preparation of medicamentsuseful for such methods.

In a method of treatment aspect, provided herein is a method of treatinga mammal susceptible to or afflicted with a condition associated witharthritis, asthma, myocardial infarction, inflammatory bowel disease andautoimmune disorders, which method comprises administering an effectiveamount of one or more of the pharmaceutical compositions just described.

In yet another method of treatment aspect, provided herein is a methodof treating a mammal susceptible to or afflicted with a condition thatgives rise to pain responses or that relates to imbalances in themaintenance of basal activity of sensory nerves. The present compoundshave use as analgesics for the treatment of pain of various geneses oretiology, for example acute, inflammatory pain (such as pain associatedwith osteoarthritis and rheumatoid arthritis); various neuropathic painsyndromes (such as post-herpetic neuralgia, trigeminal neuralgia, reflexsympathetic dystrophy, diabetic neuropathy, Guillian Barre syndrome,fibromyalgia, phantom limb pain, post-masectomy pain, peripheralneuropathy, HIV neuropathy, and chemotherapy-induced and otheriatrogenic neuropathies); visceral pain, (such as that associated withgastroesophageal reflex disease, irritable bowel syndrome, inflammatorybowel disease, pancreatitis, and various gynecological and urologicaldisorders), dental pain and headache (such as migraine, cluster headacheand tension headache).

In additional method of treatment aspects, provided herein are methodsof treating a mammal susceptible to or afflicted with neurodegenerativediseases and disorders such as, for example Parkinson's disease,Alzheimer's disease and multiple sclerosis; diseases and disorders whichare mediated by or result in neuroinflammation such as, for exampleencephalitis; centrally-mediated neuropsychiatric diseases and disorderssuch as, for example depression mania, bipolar disease, anxiety,schizophrenia, eating disorders, sleep disorders and cognitiondisorders; epilepsy and seizure disorders; prostate, bladder and boweldysfunction such as, for example urinary incontinence, urinaryhesitancy, rectal hypersensitivity, fecal incontinence, benign prostatichypertrophy and inflammatory bowel disease; respiratory and airwaydisease and disorders such as, for example, allergic rhinitis, asthmaand reactive airway disease and chronic obstructive pulmonary disease;diseases and disorders which are mediated by or result in inflammationsuch as, for example rheumatoid arthritis and osteoarthritis, myocardialinfarction, various autoimmune diseases and disorders; itch/pruritussuch as, for example psoriasis; obesity; lipid disorders; cancer; andrenal disorders method comprises administering an effectivecondition-treating or condition-preventing amount of one or more of thepharmaceutical compositions just described.

As a further aspect there is provided the present fused heterocycliccompounds for use as a pharmaceutical especially in the treatment orprevention of the aforementioned conditions and diseases. We alsoprovide the use of the present compounds in the manufacture of amedicament for the treatment or prevention of one of the aforementionedconditions and diseases.

Injection dose levels range from about 0.1 mg/kg/hour to at least 10mg/kg/hour, all for from about 1 to about 120 hours and especially 24 to96 hours. A preloading bolus of from about 0.1 mg/kg to about 10 mg/kgor more may also be administered to achieve adequate steady statelevels. The maximum total dose is not expected to exceed about 2 g/dayfor a 40 to 80 kg human patient.

For the prevention and/or treatment of long-term conditions, such asneurodegenerative and autoimmune conditions, the regimen for treatmentusually stretches over many months or years so oral dosing is preferredfor patient convenience and tolerance. With oral dosing, one to five andespecially two to four and typically three oral doses per day arerepresentative regimens. Using these dosing patterns, each dose providesfrom about 0.01 to about 20 mg/kg of the compound provided herein, withpreferred doses each providing from about 0.1 to about 10 mg/kg andespecially about 1 to about 5 mg/kg.

Transdermal doses are generally selected to provide similar or lowerblood levels than are achieved using injection doses.

When used to prevent the onset of a neurodegenerative, autoimmune orinflammatory condition, the compounds provided herein will beadministered to a patient at risk for developing the condition,typically on the advice and under the supervision of a physician, at thedosage levels described above. Patients at risk for developing aparticular condition generally include those that have a family historyof the condition, or those who have been identified by genetic testingor screening to be particularly susceptible to developing the condition.

The compounds provided herein can be administered as the sole activeagent or they can be administered in combination with other agents,including other active amines and derivatives. Administration incombination can proceed by any technique apparent to those of skill inthe art including, for example, separate, sequential, concurrent andalternating administration.

General Synthetic Procedures

The fused heterocyclic compounds provided herein can be prepared fromreadily available starting materials using the following general methodsand procedures. See, e.g., FIG. 1 and Synthetic Schemes 1 and 2, below.It will be appreciated that where typical or preferred processconditions (i.e., reaction temperatures, times, mole ratios ofreactants, solvents, pressures, etc.) are given, other processconditions can also be used unless otherwise stated. Optimum reactionconditions may vary with the particular reactants or solvent used, butsuch conditions can be determined by one skilled in the art by routineoptimization procedures.

Additionally, as will be apparent to those skilled in the art,conventional protecting groups may be necessary to prevent certainfunctional groups from undergoing undesired reactions. The choice of asuitable protecting group for a particular functional group as well assuitable conditions for protection and deprotection are well known inthe art. For example, numerous protecting groups, and their introductionand removal, are described in T. W. Greene and P. G. M. Wuts, ProtectingGroups in Organic Synthesis, Second Edition, Wiley, New York, 1991, andreferences cited therein.

The compounds provided herein, for example, may be prepared by thereaction of a chloro derivative with an appropriately substituted amineand the product isolated and purified by known standard procedures. Suchprocedures include (but are not limited to) recrystallization, columnchromatography or HPLC. The following schemes are presented with detailsas to the preparation of representative fused heterocyclics that havebeen listed hereinabove. The compounds provided herein may be preparedfrom known or commercially available starting materials and reagents byone skilled in the art of organic synthesis.

The enantiomerically pure compounds provided herein may be preparedaccording to any techniques known to those of skill in the art. Forinstance, they may be prepared by chiral or asymmetric synthesis from asuitable optically pure precursor or obtained from a racemate by anyconventional technique, for example, by chromatographic resolution usinga chiral column, TLC or by the preparation of diastereoisomers,separation thereof and regeneration of the desired enantiomer. See,e.g., “Enantiomers, Racemates and Resolutions,” by J. Jacques, A.Collet, and S. H. Wilen, (Wiley-Interscience, New York, 1981); S. H.Wilen, A. Collet, and J. Jacques, Tetrahedron, 2725 (1977); E. L. ElielStereochemistry of Carbon Compounds (McGraw-Hill, NY, 1962); and S. H.Wilen Tables of Resolving Agents and Optical Resolutions 268 (E. L.Eliel ed., Univ. of Notre Dame Press, Notre Dame, Ind., 1972,Stereochemistry of Organic Compounds, Ernest L. Eliel, Samuel H. Wilenand Lewis N. Manda (1994 John Wiley & Sons, Inc.), and StereoselectiveSynthesis A Practical Approach, Mihály Nógrádi (1995 VCH Publishers,Inc., NY, N.Y.).

In certain embodiments, an enantiomerically pure compound of formula 1may be obtained by reaction of the racemate with a suitable opticallyactive acid or base. Suitable acids or bases include those described inBighley et al., 1995, Salt Forms of Drugs and Adsorption, inEncyclopedia of Pharmaceutical Technology, vol. 13, Swarbrick & Boylan,eds., Marcel Dekker, New York; ten Hoeve & H. Wynberg, 1985, Journal ofOrganic Chemistry 50:4508-4514; Dale & Mosher, 1973, J. Am. Chem. Soc.95:512; and CRC Handbook of Optical Resolution via Diastereomeric SaltFormation, the contents of which are hereby incorporated by reference intheir entireties.

Enantiomerically pure compounds can also be recovered either from thecrystallized diastereomer or from the mother liquor, depending on thesolubility properties of the particular acid resolving agent employedand the particular acid enantiomer used. The identity and optical purityof the particular compound so recovered can be determined by polarimetryor other analytical methods known in the art. The diasteroisomers canthen be separated, for example, by chromatography or fractionalcrystallization, and the desired enantiomer regenerated by treatmentwith an appropriate base or acid. The other enantiomer may be obtainedfrom the racemate in a similar manner or worked up from the liquors ofthe first separation.

In certain embodiments, enantiomerically pure compound can be separatedfrom racemic compound by chiral chromatography. Various chiral columnsand eluents for use in the separation of the enantiomers are availableand suitable conditions for the separation can be empirically determinedby methods known to one of skill in the art. Exemplary chiral columnsavailable for use in the separation of the enantiomers provided hereininclude, but are not limited to CHIRALCEL® OB, CHIRALCEL® OB-H,CHIRALCEL® OD, CHIRALCEL® OD-H, CHIRALCEL® OF, CHIRALCEL® OG, CHIRALCEL®OJ and CHIRALCEL® OK.

Substituted2-(4-(alkylamino)-7,8-dihydropyrido[4,3-d]pyrimidin-6(5H)-yl)benzonitrilederivative is prepared by first reacting the6-benzyl-5,6,7,8-tetrahydro-3H-pyrido[4,3-d]pyrimidin-4-one with POCl₃and reacting the product with an appropriately substituted amine to giveN-substituted 6-benzyl-5,6,7,8-tetrahydropyrido[4,3-d]pyrimidin-4-aminewhich is subjected to removal of the benzyl group followed bycondensation with an appropriate 2-halo-benzonitrile using S_(N)Ar orBuchwald coupling reaction to yield the appropriate N-substituted2-(4-amino-7,8-dihydro-5H-pyrido[4,3-d]pyrimidin-6-yl)-benzonitrile. Thegeneral synthesis method is depicted in Scheme 1.

Various N-substituted2-(4-amino-7,8-dihydropyrido[4,3-d]pyrimidin-6(5H)-yl)benzonitriles areprepared using a general procedure shown above (Scheme 2).6-Benzyl-5,6,7,8-tetrahydropyrido[4,3-d]pyrimidin-4(3H)-one is treatedwith POCl₃ to give6-benzyl-4-chloro-5,6,7,8-tetrahydropyrido[4,3-d]pyrimidine which istreated with sodium methoxide to give6-benzyl-4-methoxy-5,6,7,8-tetrahydropyrido[4,3-d]pyrimidine.Debenzylation and reacting the product with an appropriate2-halo-benzonitrile under S_(N)Ar or Buchwald coupling reactionconditions give the2-(4-methoxy-7,8-dihydropyrido[4,3-d]pyrimidin-6(5H)-yl)benzonitrilewhich is reacted with POCl₃ or POBr₃. Displacement of the resultant4-chloro or 4-bromo group using appropriately substituted amines viaS_(N)Ar displacement affords various N-substituted2-(4-amino-7,8-dihydropyrido[4,3-d]pyrimidin-6(5H)-yl)benzonitriles.

The following synthetic and biological examples are offered toillustrate the compounds, pharmaceutical compositions and methodsprovided herein and are not to be construed in any way as limiting thescope provided herein. In the examples below, all temperatures are indegrees Celsius (unless otherwise indicated). The syntheses of theserepresentative compounds are carried out in accordance with the methodsset forth above and using the appropriate reagents, starting materials,and purification methods known to those skilled in the art.

Exemplary Compounds Provided Herein

The following compounds can be prepared according to the methodsprovided herein. Unless otherwise indicated, reactions in microwave werecarried out in Biotage Initiator microwave synthesizer manufactured byBiotage AB, Inc. or Emrys Optimizer microwave model manufactured byPersonal Chemistry, Inc.

Synthesis of Intermediates Intermediate 16-Benzyl-5,6,7,8-tetrahydropyrido[4,3-d]pyrimidin-4(3H)-one

A mixture of ethyl 1-benzyl-4-oxopiperidine-3-carboxylate hydrochloride(50.0 g, 0.168 mol), formamidine acetate (16.2 g, 0.201 mol), 4.37 M ofsodium methoxide in methanol (190 mL) and methanol (200 mL) was heatedat 85° C. for 16 hour in a 350 mL sealed reaction vessel. The mixturewas allowed to cool and concentrated in vacuo. The residue was dissolvedin 1N NaOH (150 mL) and poured over ice. Glacial acetic acid was addedto the mixture until the pH of the mixture was 7 and a tan solidprecipitated out. The solid was filtered, washed with water and coldether, and dried on high vacuum to yield the title compound as a tansolid (26.2 g, 61.4%).

LC-MS: 242.2 [M+1]⁺; ¹H NMR (400 MHz, DMSO-d₆): δ 2.29 (t, 2H, J=5.8Hz), 2.61 (t, 2H, J=5.8 Hz), 3.26 (s, 2H), 3.64 (s, 2H), 7.21-7.36 (m,6H), 7.96 (s, 1H).

Intermediate 26-Benzyl-4-chloro-5,6,7,8-tetrahydropyrido[4,3-d]pyrimidine

A mixture of 6-benzyl-5,6,7,8-tetrahydropyrido[4,3-d]pyrimidin-4(3H)-one(5.0 g, 0.02 mol), phosphoryl chloride (3.30 mL, 0.035 mol) andacetonitrile (80 mL) and DMF (catalytic amount) was heated at 70° C. for1 hour. The mixture was concentrated in vacuo and the remaining blackresidue was taken up in dichloromethane (250 mL) and poured over ice.The mixture was carefully neutralized with the addition of solid sodiumbicarbonate. The organic layer was separated and dried over sodiumsulfate and concentrated in vacuo. The mixture was purified by silicagel column with EtOAc/hexane (0-100%) to yield the title compound as ayellow oil (3 g, 57.8%).

LC-MS: 260 [M+1]⁺; ¹H NMR (400 MHz, DMSO-d₆): δ 8.80 (s, 1H), 7.40-7.24(m, 5H), 3.76 (s, 2H), 3.57 (s, 2H), 2.92 (t, 2H), 2.80 (t, 2H).

Intermediate 3 4-Methoxy-5,6,7,8-tetrahydropyrido[4,3-d]pyrimidine

A) 6-Benzyl-4-methoxy-5,6,7,8-tetrahydropyrido[4,3-d]pyrimidine

A 1 L flask was charged with6-benzyl-4-chloro-5,6,7,8-tetrahydropyrido[4,3-d]pyrimidine (39.6 g,0.152 mol) and methanol (300 mL), and the mixture was heated to dissolvethe chloropyrimidine. 4.37 M of sodium methoxide in methanol (105 mL)was added slowly to the warm mixture and the stirred mixture rapidlyturned cloudy. The resultant suspension was heated under reflux for 2 h.After cooling, the mixture was concentrated in vacuo to ca 100 mL. Theresidue was poured into water (600 mL), and extracted with CH₂Cl₂ (200mL×2). The combined organic layers were washed with brine (400 mL),dried (Na₂SO₄), filtered and concentrated in vacuo to yield a lightbrown oil (38.9 g, 100%).

LC-MS: 256.1 [M+H]⁺

B) 4-Methoxy-5,6,7,8-tetrahydropyrido[4,3-d]pyrimidine

250 mL flask was charged with6-benzyl-4-methoxy-5,6,7,8-tetrahydropyrido[4,3-d]pyrimidine (4.08 g,16.0 mmol), 10% palladium on charcoal (400 mg) and methanol (100 mL).The reaction was evacuated and purged with hydrogen three times, andhydrogenated (1 atm) overnight. The mixture was filtered through a “Drydisk” membrane filter, and concentrated in vacuo to yield an orange oil(2.56 g).

¹H NMR (400 MHz, CDCl₃): δ 8.57 (s, 1H), 3.99 (s, 3H), 3.87 (s, 2H),3.18 (t, 2H, J=6.9 Hz), 2.82 (t, 2H, J=6.9 Hz).

Intermediate 42-(4-Bromo-7,8-dihydropyrido[4,3-d]pyrimidin-6(5H)-yl)-5-chlorobenzonitrile

A)5-Chloro-2-(4-methoxy-7,8-dihydropyrido[4,3-d]pyrimidin-6(5H)-yl)benzonitrileand5-chloro-2-(4-hydroxy-7,8-dihydropyrido[4,3-d]pyrimidin-6(5H)-yl)benzonitrile

A 20 mL microwave vial was charged with4-methoxy-5,6,7,8-tetrahydropyrido[4,3-d]pyrimidine (1.88 g, 11.4 mmol),5-chloro-2-fluorobenzonitrile (2.8 g, 18 mmol),N,N-diisopropylethylamine (3.0 mL), and acetonitrile (5 mL). The mixturewas subjected to microwave irradiation at 200° C. for 3.5 h. The mixturewas diluted with chloroform (50 mL), washed with 0.3 M aqueous NaH₂PO₄(75 mL), then extracted with 2M KOH (20 mL×2). The organic layercontaining the methoxy-pyrimidine was dried (Na₂SO₄), filtered andconcentrated to a brown-red solid, which was purified by silica gelcolumn (0-4% MeOH/CH₂Cl₂) to yield a brown oil (0.43 g). The combinedaqueous KOH extracts were acidified with 1M aqueous H₂SO₄, and extractedwith chloroform (30 mL×2), dried (Na₂SO₄), filtered and concentrated toafford the crude hydroxy-pyrimidine as a brown solid (0.84 g).

LC-MS: 287.3 [M+H]⁺

B)2-(4-Bromo-7,8-dihydropyrido[4,3-d]pyrimidin-6(5H)-yl)-5-chlorobenzonitrile

POBr₃ (1.61 g, 5.6 mmol) was added portionwise over 2 min to a mixtureof5-chloro-2-(4-hydroxy-7,8-dihydropyrido[4,3-d]pyrimidin-6(5H)-yl)benzonitrile(0.82 g, 2.8 mmol), N,N-dimethylaniline (0.7 mL), andN,N-dimethylformamide (0.02 mL) in acetonitrile (10 mL) and anisole (10mL). The mixture was heated under reflux for 2.5 h and LC-MS showedreaction was complete. After cooling the mixture was diluted withchloroform (20 mL) and poured into a stirred mixture of ice (50 g), 50%KOH (8 mL) and chloroform (100 mL). The organic layer was separated andthe aqueous layer was extracted with chloroform (25 mL×2). The combinedorganic layers were washed with brine (100 mL), dried (Na₂SO₄), filteredand concentrated. The residue was purified by silica gel column to yielda brown solid (0.35 g).

¹H NMR (400 MHz, CDCl₃): δ 8.85 (s, 1H), 7.61 (d, 1H, J=2.4 Hz), 7.52(dd, 1H, J=8.8, 2.4 Hz), 7.11 (d, 1H, J=8.8 Hz), 4.34 (s, 2H), 3.68 (t,2H, J=5.6 Hz), 3.27 (t, 2H, J=5.6 Hz).

Intermediate 52-(4-Chloro-7,8-dihydropyrido[4,3-d]pyrimidin-6(5H)-yl)-5-methylbenzonitrile

A)2-(4-Methoxy-7,8-dihydropyrido[4,3-d]pyrimidin-6(5H)-yl)-5-methylbenzonitrile

A 100 mL flask was charged with4-methoxy-5,6,7,8-tetrahydropyrido[4,3-d]pyrimidine (2.78 g, 16 mmol),2-bromo-5-methylbenzonitrile (4.18 g, 19.2 mmol),bis(dibenzylideneacetone)palladium(0) (372 mg, 0.64 mmol), xantphos (529mg, 0.896 mmol), and sodium tert-butoxide (2.33 g, 24 mmol), capped witha septum and purged with nitrogen. Dry argon-sparged toluene (50 mL) wasadded. The hetergeneous mixture was placed in an oil bath at 100° C.,and heated under argon overnight. After 14 hours, TLC showed thereaction was complete. The mixture was removed from the heat, dilutedwith ethyl acetate (50 mL), filtered and concentrated in vacuo. Theresidue was purified by silica gel column (0-100% EtOAc/hexane) toafford a light orange solid.

B)2-(4-Chloro-7,8-dihydropyrido[4,3-d]pyrimidin-6(5H)-yl)-5-methylbenzonitrile

A mixture of2-(4-methoxy-7,8-dihydropyrido[4,3-d]pyrimidin-6(5H)-yl)-5-methylbenzonitrile(4.15 g, 14.1 mmol), N,N-dimethylaniline (0.18 mL, 1.4 mmol),N,N-dimethylformamide (0.21 mL, 2.7 mmol) and acetonitrile (35 mL) washeated to dissolve at 105° C. Phosphoryl chloride (5.3 mL, 56 mmol) wasadded dropwise over 3 mins, and the reaction was heated to reflux at110° C. After 40 mins, additional phosphoryl chloride (5.3 mL, 0.056mol) was added dropwise over 3 mins. After another 20 hours, ¹H NMRshowed that the reaction was ca 70% complete and the reaction mixturewas allowed to cool and poured over ice (200 g) and 45% aq. NaOH (75 mL)was added. The mixture was extracted with CH₂Cl₂ (3×200 mL). Thecombined organic layers were dried over sodium sulfate and concentrated.The residue was purified by silica gel column (0-100% EtOAc/hexane) toyield a brown oil which became a solid in the freezer.

LC-MS: 285.5 [M+H]⁺

¹H NMR (300 MHz, CDCl₃): δ 8.81 (s, 1H), 7.42 (d, 1H, J=2.1 Hz), 7.34(dd, 1H, J=8.4, 2.1 Hz), 7.04 (d, 1H, J=8.4 Hz), 4.29 (s, 2H), 3.60 (t,2H, J=5.7 Hz), 3.23 (t, 2H, J=5.7 Hz), 2.32 (s, 3H).

Intermediate 65-Chloro-2-(4-chloro-7,8-dihydropyrido[4,3-d]pyrimidin-6(5H)-yl)benzonitrile

A)5-Chloro-2-(4-methoxy-7,8-dihydropyrido[4,3-d]pyrimidin-6(5H)-yl)benzonitrile

A mixture of 4-methoxy-5,6,7,8-tetrahydropyrido[4,3-d]pyrimidine (12.88g, 0.078 mol), 5-chloro-2-fluorobenzonitrile (40 g, 0.2 mol), and1,8-diazabicyclo[5.4.0]undec-7-ene (60 mL, 0.4 mol) was heated at 80° C.for 3 hours. After cooling the mixture was diluted with CH₂Cl₂ (300 mL),washed with water, dried, and concentrated to afford a brown solid whichwas purified by silica gel chromatography (0-50% EtOAc/hexane) to afforda solid (19.33 g, 78.3%).

B)5-Chloro-2-(4-chloro-7,8-dihydropyrido[4,3-d]pyrimidin-6(5H)-yl)benzonitrile

A mixture of5-chloro-2-(4-methoxy-7,8-dihydropyrido[4,3-d]pyrimidin-6(5H)-yl)benzonitrile(4.15 g, 13.1 mmol), N,N-dimethylaniline (0.18 mL, 1.4 mmol),N,N-dimethylformamide (0.21 mL, 2.7 mmol) and acetonitrile (35 mL) washeated to dissolve at 105° C. Phosphoryl chloride (5.3 mL, 56 mmol) wasadded dropwise over 3 mins and the mixture was heated to reflux at 110°C. After another 20 hours refluxing, the reaction mixture was allowed tocool and poured over ice (200 g), and then 45% NaOH (75 mL) was added.The mixture was extracted with CH₂Cl₂ (3×200 mL). The combined organiclayers were dried over sodium sulfate, and concentrated. The residue waspurified by silica gel chromatography (0-100% EtOAc/hexane) to afford ayellow oil which became a solid in the freezer.

¹H NMR (300 MHz, CDCl₃): δ 8.83 (s, 1H), 7.59 (d, 1H, J=2.4 Hz), 7.50(dd, 1H, J=8.7, 2.4 Hz), 7.09 (d, 1H, J=8.7 Hz), 4.32 (s, 2H), 3.66 (t,2H, J=5.7 Hz), 3.25 (t, 2H, J=5.7 Hz).

Intermediates 7 and 8 (R)-1-(6-(Trifluoromethyl)pyridin-3-yl)ethanamineand (S)-1-(6-(trifluoromethyl)pyridin-3-yl)ethanamine

A) N-methoxy-N-methyl-6-(trifluoromethyl)nicotinamide

To a stirred mixture of N,O-dimethylhydroxylamine hydrochloride (9.47 g,97.1 mmol) and pyridine (18.6 mL, 230 mmol) in CH₂Cl₂ (100 mL) was addeda solution of 6-(trifluoromethyl)nicotinoyl chloride (18.50 g, 88.28mmol) in CH₂Cl₂ (250 mL) over 3-5 min. The reaction mixture was stirredat rt overnight, and then carefully quenched with 150 mL of saturatedaq. NaHCO₃ solution and stirred for about 1 hr. The mixture was dilutedwith CH₂Cl₂ (50 mL) and the organic phase was separated and washed withaq. NaHCO₃ solution (100 mL) and brine (50 mL), dried (Na₂SO₄),filtered, and evaporated. The residue was redissolved in toluene (about50 mL) and evaporated again to azeotrope the pyridine off. This wasrepeated with toluene (about 50 mL). The product was isolated as acolorless oil (with a small amount of crystalline material) (19.1 g,92%).

LC-MS: 235.4 [M+1]⁺;

¹H NMR (400 MHz, CDCl₃): δ 9.05 (d, 1H, J=1.6 Hz), 8.22 (dd, 1H, J=8.0,1.6 Hz), 7.76 (d, 1H, J=8.0 Hz), 3.57 (s, 3H), 3.42 (s, 3H).

B) 1-(6-(trifluoromethyl)pyridin-3-yl)ethanone

N-Methoxy-N-methyl-6-(trifluoromethyl)nicotinamide (19.1 g, 81.6 mmol)was dissolved in tetrahydrofuran (410 mL). The system was purged with N₂and then cooled to 0° C. 1.4 M of methylmagnesium bromide in toluene/THF(75:25) (87.4 mL, 122.4 mmol) was added dropwise using an additionalfunnel. At the end of the addition the mixture was cloudy off-white. Themixture was stirred at 0° C. for 1 hour and carefully quenched bydropwise addition of 1 M aq. HCl (150 mL) and diluted with ethyl ether(300 mL) and EtOAc (100 mL). The organic layer was separated and washedwith 0.1 M aq. NaOH (200 mL) and brine (2×50 mL), dried (Na₂SO₄), andconcentrated to yield a light yellow solid (15.04 g, 98%).

LC-MS: 190.2 [M+1]⁺; ¹H NMR (400 MHz, CDCl₃): δ 9.25 (d, 1H, J=1.6 Hz),8.42 (dd, 1H, J=8.0, 1.6 Hz), 7.82 (d, 1H, J=8.0 Hz), 2.70 (s, 3H).

C)(R)-2-methyl-N—((R)-1-(6-(trifluoromethyl)pyridin-3-yl)ethyl)propane-2-sulfinamideand(R)-2-methyl-N—((S)-1-(6-(trifluoromethyl)pyridin-3-yl)ethyl)propane-2-sulfinamide

To a solution of 1-(6-(trifluoromethyl)pyridin-3-yl)ethanone (15.0 g,79.3 mmol) in tetrahydrofuran (450 mL) under N₂ was addedtetraethoxytitanium (28.8 mL, 132 mmol). Solid(R)-(+)-2-methylpropane-2-sulfinamide (8.01 g, 66.1 mmol) was then addedand the reaction was heated under reflux overnight. The resulting iminesolution was cooled to −45 to −50° C. and cannulated into flaskcontaining sodium tetrahydroborate (12.5 g, 330 mmol) andtetrahydrofuran (100 mL) that was cooled to −45 to −50° C. The resultingcloudy orange solution was stirred at −40° C. for 4 h and then slowlywarmed to rt and stirred at rt for 2 days. After cooling to 0° C., thereaction mixture was carefully quenched by dropwise addition of MeOH(100 mL) followed by dropwise addition of water (40 mL). The mixture wasstirred for about 20 minutes, and then rotovapped to dryness. EtOAc (500mL) was added and the mixture was stirred for about 1 hr, and then brine(50 mL) was added portionwise. The mixture was filtered through Celiteand the filter cake was washed with EtOAc (3×100 mL). The filtrate waswashed with saturated aq. NaHCO₃, water, and brine, dried (Na₂SO₄),concentrated to yield a light yellow waxy solid (22.40 g, 96%). ¹H NMRof the crude product indicates about 93:7 ratio of two diastereomers.The product was recrystallized from EtOAc (150 mL) and washed with coldEtOAc (3×20 mL) to yield a white crystalline solid (12.22 g, 52.5%) asthe (R,R)-isomer. The mother liquor was concentrated and purified bysilica gel column chromatography to yield additional (R,R)-isomer (5 g,21%) and the (R,S)-isomer (1.1 g) which was recrystallized frommethylcyclohexane to yield an off white solid. ¹H NMR (CDCl₃ andDMSO-d6) of each recrystallized fraction (R,R and R,S) indicated lessthan 1% of the other isomer and good purities in all cases.

(R,R)-isomer: LC-MS: 295.4 [M+1]⁺;

¹H NMR (400 MHz, CDCl₃): δ 8.73 (d, 1H, J=1.6 Hz), 7.90 (dd, 1H, J=8.0,2.4 Hz), 7.69 (d, 1H, J=8.0 Hz), 4.68 (m, 1H), 3.53 (d, 1H, J=3.6 Hz),1.59 (d, 3H, J=6.8 Hz), 1.25 (s, 9H). ¹H NMR (d6-DMSO): 8.80 (d, 1H,J=1.6 Hz), 8.11 (dd, 1H, J=8.0, 2.0 Hz), 7.90 (d, 1H, J=8.0 Hz), 5.94(d, 1H, J=7.6 Hz), 4.57 (p, 1H, J=7.2 Hz), 1.46 (d, 3H, J=7.2 Hz), 1.13(s, 9H).

(R,S)-isomer: ¹H NMR (400 MHz, CDCl₃): 8.73 (d, 1H, J=1.6 Hz), 7.84 (dd,1H, J=8.0, 1.6 Hz), 7.67 (d, 1H, J=8.0 Hz), 4.72 (m, 1H), 3.42 (d, 1H,J=2.4 Hz), 1.60 (d, 3H, J=6.8 Hz), 1.23 (s, 9H).

¹H NMR (d6-DMSO): 8.77 (d, 1H, J=1.6 Hz), 8.06 (dd, 1H, J=8.0, 2.0 Hz),7.90 (d, 1H, J=8.0 Hz), 5.67 (d, 1H, J=6.0 Hz), 4.62 (p, 1H, J=6.4 Hz),1.52 (d, 3H, J=6.8 Hz), 1.12 (s, 9H).

D) (R)-1-(6-(trifluoromethyl)pyridin-3-yl)ethanamine

(R)-2-Methyl-N—((R)-1-(6-(trifluoromethyl)pyridin-3-yl)ethyl)propane-2-sulfinamide(12.75 g, 43.32 mmol) was added to a 200 mL flask followed by additionof 1,4-dioxane (58 mL). 6.0 M of aqueous HCl (28.9 mL) was added and thereaction was stirred at rt for 1.5 hrs to ensure all of the sulfinylchloride was destroyed. The solvent was evaporated and the residue wastreated with CH₂Cl₂ (200 mL) and 1 M aq. NaOH (200 mL). The organiclayer was separated and the aqueous layer was extracted with CH₂Cl₂(2×50 mL). The organic layers were combined and dried with Na₂SO₄, andconcentrated to obtain a clear colorless liquid (8.30 g). Chiral HPLCanalysis (ChiralPac AD-H column 250×4.6 mm, hexane/PrOH/Et₂NH:95/5/0.05): 97.8% R-isomer (10.69 min), 0.63% S-isomer (9.63 min).

LC-MS: 191.2 [M+1]⁺;

¹H NMR (400 MHz, CDCl₃): δ 8.72 (d, 1H, J=1.6 Hz), 7.92 (dd, 1H, J=8.0,2.0 Hz), 7.66 (d, 1H, J=8.0 Hz), 4.30 (q, 1H, J=6.8 Hz), 1.62 (s, 2H),1.43 (d, 3H, J=6.8 Hz).

E) (S)-1-(6-(trifluoromethyl)pyridin-3-yl)ethanamine

To(R)-2-Methyl-N—((S)-1-(6-(trifluoromethyl)pyridin-3-yl)ethyl)propane-2-sulfinamide(355 mg, 1.21 mmol) in a 20 mL scintilation vial was added 1,4-dioxane(1.6 mL) and 6.0 M of aq. HCl (0.80 mL). The reaction was stirred at rtfor about 2 hours and then the dioxane was evaporated. Water (3 mL) wasadded and 1 M aq. NaOH was added until pH>12 was attained. The basicaqueous was extracted with CH₂Cl₂ (5 mL×2). The combined organic layerswere dried with Na₂SO₄, filtered and evaporated to obtain a clear lightyellow liquid (123 mg, 54%). Chiral HPLC analysis (ChiralPac AD-H column250×4.6 mm, hexane/'PrOH/Et₂NH: 95/5/0.05): 97% S-isomer (9.61 min), nosignificant evidence of R-isomer at 10.7 min.

LC-MS: 191.2 [M+1]⁺;

¹H NMR (400 MHz, CDCl₃): δ 8.72 (d, 1H, J=1.6 Hz), 7.92 (dd, 1H, J=8.0,2.0 Hz), 7.66 (d, 1H, J=8.0 Hz), 4.30 (q, 1H, J=6.8 Hz), 1.55 (s, 2H),1.43 (d, 3H, J=6.8 Hz).

Intermediate 9 (5-Cyclopropylpyridin-2-yl)methanamine

A) 2-Cyano-5-cyclopropylpyridine

To a mixture of 5-chloro-2-cyanopyridine (1.25 g, 9.02 mmol),cyclopropylboronic acid (1.00 g, 11.7 mmol), potassium phosphate (6.70g, 31.6 mmol), tricyclohexylphosphine (380 mg, 1.4 mmol), toluene (200mL), and water (2 mL) under argon was added palladium acetate (150 mg,0.68 mmol). The mixture was heated at 100° C. overnight and then cooledto rt. The mixture was filtered through Celite and the filter cake waswashed with EtOAc. The filtrate was washed with water, dried (Na₂SO₄),and concentrated. The residue was purified by silica gel column(EtOAc/hexane: 0-50%) to yield a light yellow oil which becomes solidwhile standing at room temperature.

LC-MS: 145.3 [M+H]⁺

¹H NMR (400 MHz, CDCl₃): δ 8.49 (d, 1H, J=2.4 Hz), 7.57 (d, 1H, J=8.0Hz), 7.37 (dd, 1H, J=8.0, 2.4 Hz), 1.97 (m, 1H), 1.18 (m, 2H), 0.83 (m,2H).

B) (5-Cyclopropylpyridin-2-yl)methanamine

To a solution of 2-cyano-5-cyclopropylpyridine (210 mg, 1.4 mmol) in 20mL of 7.0 M ammonia in MeOH was added a small spoon of Raney Ni slurry.The mixture was hydrogenated at 50 psi overnight. The catalyst wasfiltered off and the filtrate was concentrated to yield a dark oil whichwas used for the next step reaction without further purification.

LC-MS: 149.2 [M+H]⁺

Intermediate 10 (S)-2-Amino-2-(6-methoxypyridin-3-yl)ethanol

A) 2-Methoxy-5-vinylpyridine

A suspension of triphenylmethylphosphonium bromide (31.2 g, 0.0875 mol)in THF (150 mL) at −78° C. under an atmosphere of nitrogen was added 2.5M n-BuLi (38.0 mL, 0.0948 mol) in hexane during a period of 30 min. Thereaction was warmed to room temperature to yield a deep red ylidesolution. To the ylide solution, cooled in ice, was introduced6-methoxynicotinaldehyde (10.0 g, 0.0729 mol) in THF (30 mL). Thereaction was allowed to reach room temperature and stirred at roomtemperature for 3 h. Then the result suspension was heated to 60° C.over 30 minutes and heated at 60° C. for 1 hour. After cooling, thereaction was diluted with water (500 mL). The product was extracted intoethyl ether, washed with brine, dried (MgSO₄), and concentrated. Theresidue was purified by silica gel column (0-40% EtOAc/hexane) to yielda light yellow oil. LC-MS: 136.0 [M+1]⁺;

¹H NMR (400 MHz, CDCl₃): δ 8.12 (d, 1H, J=2.4 Hz), 7.70 (dd, 1H, J=8.4,2.4 Hz), 6.72 (d, 1H, J=8.4 Hz), 6.65 (dd, 1H, J=17.6, 11.2 Hz), 5.64(d, 1H, J=17.6 Hz), 5.22 (d, 1H, J=11.2 Hz), 3.94 (s, 3H).

B) (R)-1-(6-Methoxypyridin-3-yl)ethane-1,2-diol

A 500 mL flask was charged with tert-butyl alcohol (130 mL), water (130mL), and AD-mix-β (36.5 g). Stirring at rt produced two clear phases;the lower aqueous phase appears bright yellow. The mixture was cooled to0° C. whereupon some of the dissolved salts precipitated.2-Methoxy-5-vinylpyridine (3.5 g, 26 mmol) was added at once, and theheterogeneous slurry was stirred vigorously at 0° C. for 6 h. LC-MSindicated completion of the reaction. While the mixture was stirred at0° C., solid sodium sulfite (39 g) was added and the mixture was allowedto warm to rt and stirred for 1 h. EtOAc (250 mL) was added to thereaction mixture, and after separation of the layers, the aqueous phasewas further extracted with EtOAc (3×100 mL). The combined organic layerswere dried over anhydrous MgSO₄ and concentrated in vacuo. The residuewas purified by silica gel column (0-100% EtOAc/hexane) to yield thediol as a white solid (2.76 g, 63%). LC-MS: 170.2 [M+1]⁺.

C) (R)-2-Hydroxy-2-(6-methoxypyridin-3-yl)ethyl 4-methylbenzenesulfonate

To a stirred solution of (R)-1-(6-methoxypyridin-3-yl)ethane-1,2-diol(2.7 g, 0.016 mol) and pyridine (10 mL) in CH₂Cl₂ (100 mL) at 0° C. wasadded p-toluenesulfonyl chloride (3.6 g, 0.019 mol) in small portions.The mixture was slowly warmed to rt and stirred for 24 h, and thendiluted with CH₂Cl₂ (100 mL). The organic phase was washed with aq.NaHCO₃, brine, dried (Na₂SO₄), and concentrated to yield a solid (6.0g). LC-MS: 324.0 [M+H]⁺.

D) (R)-2-Methoxy-5-(oxiran-2-yl)pyridine

To a stirred solution of (R)-2-hydroxy-2-(6-methoxypyridin-3-yl)ethyl4-methylbenzenesulfonate in MeOH (150 mL) at 0° C. was added potassiumcarbonate (4.4 g, 0.032 mol) and the mixture was stirred at rtovernight. The mixture was filtered through Celite and the filter cakewas washed with MeOH. The filtrate was concentrated and the residue wastreated with EtOAc (150 mL) and aq. Na₂CO₃. The organic layer wasseparated and washed with brine, dried (Na₂SO₄), and concentrated. Theresidue was purified by silica gel column to yield the desired expoxideas a colorless oil (1.02 g, 42%).

¹H NMR (400 MHz, CDCl₃): δ 8.14 (d, 1H, J=2.4 Hz), 7.40 (dd, 1H, J=8.8,2.4 Hz), 6.73 (d, 1H, J=8.4 Hz), 3.93 (s, 3H), 3.84 (m, 1H), 3.16 (m,1H), 2.83 (m, 1H).

E) (S)-2-Azido-2-(6-methoxypyridin-3-yl)ethanol

To a stirred solution of (R)-2-methoxy-5-(oxiran-2-yl)pyridine (1.02 g,6.75 mmol) in acetonitrile (100 mL) were added sodium azide (1.8 g, 27mmol) and lithium perchlorate (11 g, 0.10 mol) and the mixture wasstirred at 60° C. for 4 h. TLC indicated completion of the reaction.After cooling, the mixture was filtered through Celite and the filtratewas concentrated. The residue was treated with water and extracted withEtOAc (3×50 mL). The combined organic layers were washed with aq. NaHCO₃and brine, dried (Na₂SO₄), and concentrated. The residue was purified bysilica gel column (0-50% EtOAc/hexane) to yield a light yellow oil (0.9g, 69%).

LC-MS: 195.2 [M+H]⁺;

¹H NMR (400 MHz, CDCl₃): δ 8.14 (d, 1H, J=2.4 Hz), 7.58 (dd, 1H, J=8.4,2.4 Hz), 6.79 (d, 1H, J=8.4 Hz), 4.64 (t, 1H, J=6.4 Hz), 3.95 (s, 3H),3.75 (d, 2H, J=6.4 Hz), 1.90 (bs, 1H).

F) (S)-2-Amino-2-(6-methoxypyridin-3-yl)ethanol

A mixture of (S)-2-azido-2-(6-methoxypyridin-3-yl)ethanol (0.90 g, 4.6mmol), EtOAc (50 mL), and 10% Pd—C (100 mg) was stirred under H₂ (1 atm)for 1 h. The catalyst was filtered off and the filtrate was concentratedin vacuo to yield a thick oil (0.78 g, 100%).

LC-MS: 169.2 [M+1]⁺;

¹H NMR (400 MHz, d6-DMSO): 8.08 (d, 1H, J=2.4 Hz), 7.68 (dd, 1H, J=8.4,2.4 Hz), 6.75 (d, 1H, J=8.4 Hz), 4.78 (t, 1H, J=5.6 Hz), 3.85-3.80 (m,4H), 3.38 (m, 1H), 3.31 (m, 1H), 1.83 (bs, 2H).

Intermediates 11 and 12(R)-3-Amino-3-(6-(trifluoromethyl)pyridin-3-yl)propan-1-ol and(S)-3-amino-3-(6-(trifluoromethyl)pyridin-3-yl)propan-1-ol

A) 2-(1,3-dioxolan-2-yl)-1-(6-(trifluoromethyl)pyridin-3-yl)ethanol

A suspension of 6-(trifluoromethyl)nicotinaldehyde (23.5 g, 0.134 mol)in tetrahydrofuran (500 mL) at 0° C. under an atmosphere of nitrogen wasadded 0.5 M of (1,3-dioxxlan-2-ylmethyl)-magnesium bromide solution intetrahydrofuran (400 mL, 0.20 mol), and the reaction was warmed to roomtemperature and then refluxed overnight. The reaction mixture was cooledto room temperature and quenched with water. The aqueous layer wasextracted with EtOAc and the organic layers were combined, dried overMgSO₄, filtered, and concentrated. The residue was purified by silicagel column (0-50% EtOAc/hexane) to yield a yellow oil.

B) 5-(1-azido-2-(1,3-dioxolan-2-yl)ethyl)-2-(trifluoromethyl)pyridine

A mixture of2-(1,3-dioxolan-2-yl)-1-(6-(trifluoromethyl)pyridin-3-yl)ethanol (18.54g, 0.070 mol) and diphenylphosphonic azide (36 mL, 0.17 mol) in toluene(40 mL) was cooled to 0° C. and neat 1,8-diazabicyclo[5.4.0]undec-7-ene(25 mL, 0.17 mol) was added. The reaction mixture was stirred at 0° C.for 2 hr and then at 20° C. overnight. The mixture was washed with waterand 5% HCl. The aqueous phase was extracted with CH₂Cl₂. The combinedorganic layers were concentrated in vacuo and the residue was purifiedby silica gel column (0-100% EtOAc/hexane) to afford a colorless oil.

C) 3-azido-3-(6-(trifluoromethyl)pyridin-3-yl)propanal

A solution of5-(1-azido-2-(1,3-dioxolan-2-yl)ethyl)-2-(trifluoromethyl)pyridine (7.44g, 25.8 mmol) in tetrahydrofuran (60 mL) was treated with 20% aq. HCl(60 mL) at 0° C. The mixture was stirred at room temperature for 1.5hours. After completion of the reaction, ethyl ether was added and theorganic layer was separated, dried over MgSO₄, and concentrated to yielda crude oil without further purification.

D) 3-azido-3-(6-(trifluoromethyl)pyridin-3-yl)propan-1-ol

To a stirred solution of the crude3-azido-3-(6-(trifluoromethyl)pyridin-3-yl)propanal (5.0 g, 20.5 mmol)in tetrahydrofuran (100 mL) at 0° C. was added sodium tetrahydroborate(1.52 g, 40.1 mmol). The mixture was stirred at room temperature for 10minutes. After completion of the reaction, brine was added and themixture was extracted with ether. The organic layer was dried andconcentrated to afford a crude oil which was purified by silica gelchromatography to afford a light yellow oil.

E) 3-amino-3-(6-(trifluoromethyl)pyridin-3-yl)propan-1-ol

A mixture of 3-azido-3-(6-(trifluoromethyl)pyridin-3-yl)propan-1-ol(7.29 g, 29.6 mmol), ethyl acetate (320 mL), and 10% Pd—C (3.2 g) wasstirred under H₂ (1 atm) overnight. The catalyst was filtered off andthe filtrate was concentrated in vacuo to yield the title product.

F) (S)-3-amino-3-(6-(trifluoromethyl)pyridin-3-yl)propan-1-ol and(R)-3-amino-3-(6-(trifluoromethyl)pyridin-3-yl)propan-1-ol

Racemic 3-amino-3-(6-(trifluoromethyl)pyridin-3-yl)propan-1-ol (1.10 g,5.00 mmol) was resolved by chiral HPLC (conditions: CHIRALPAK AD-Hcolumn, 20×250 mm, hexane/EtOH [88:12] at 20 mL/min, UV at 230 nm) toyield (S)-3-amino-3-(6-(trifluoromethyl)pyridin-3-yl)propan-1-ol and(R)-3-amino-3-(6-(trifluoromethyl)pyridin-3-yl)propan-1-ol. Analyticalchiral HPLC: CHIRALPAK AD-H column, 250×4.6 mm, hexane/EtOH [90:10] at1.0 mL/min, UV at 230 nm); retention time for (S)-isomer: 18.68 min(>99% ee); retention time for (R)-isomer: 23.56 min (>99% ee).

Intermediate 13 (2-Methylpyrimidin-5-yl)methanamine

A) 2-Methylpyrimidine-5-carbaldehyde

To a stirred slurry of acetamidine hydrochloride (19.4 g, 0.20 mol) andvinamidinium salt (48.91 g, 0.183 mol) in acetonitrile (240 mL) wasadded a solution of 40% wt. NaOH in water (27.4 g, 0.274 mol) over a 30minutes period. After the addition was complete, the resulting reactionmixture was stirred at room temperature overnight. The mixture wasconcentrated in vacuo and diluted with water (250 mL) and extracted withEtOAc (3×250 mL). The combined organic layers were dried over sodiumsulfate and concentrated in vacuo. The residue was purified by silicagel chromatography (0-100% EtOAc/hexanes) to afford a white solid.

B) (2-Methylpyrimidin-5-yl)methanol

A solution of 2-methylpyrimidine-5-carbaldehyde (6.48 g, 53.1 mmol) inmethanol (320 mL) was cooled to 0° C. and treated with sodiumtetrahydroborate (2.9 g, 77 mmol). After 30 min, the reaction wastreated with H₂O (50 mL) and extracted with EtOAc (250 mL×15). Theorganic layers were combined and dried over MgSO₄ and concentrated toyield a white solid.

C) 5-(Azidomethyl)-2-methylpyrimidine

A solution of (2-methylpyrimidin-5-yl)methanol (0.82 g, 6.6 mmol) intoluene (30 mL) and methylene chloride (40 mL) at 0° C. was treated withdiphenylphosphonic azide (2.8 mL, 13 mmol) followed by1,8-diazabicyclo[5.4.0]undec-7-ene (2.0 mL, 13 mmol) and stirred at 0°C. for 2 h. After being further stirred at rt for 16 h, the reactionmixture was diluted with water (50 mL) and methylene chloride (50 mL).The organic layer was separated and washed with brine, dried (Mg₂SO₄),filtered, and concentration. The residue was purified by silica gelcolumn to yield a colorless oil.

D) (2-Methylpyrimidin-5-yl)methanamine

A mixture of 5-(azidomethyl)-2-methylpyrimidine (2.0, 13.4 mmol) inethyl acetate (100 mL), and 10% Pd—C (4.0 g) was stirred under H₂ (1atm) for 1.5 hr. The catalyst was filtered off and filtrate wasconcentrated in vacuo to afford a white solid.

¹H NMR (300 MHz, CD₃OD): δ 8.67 (s, 2H), 3.81 (s, 2H), 2.66 (s, 3H).

Intermediate 14(S)-2-(tert-Butyldimethylsilyloxy)-1-(2-methoxypyrimidin-5-yl)ethanamine

A) 2-Methoxypyrimidine-5-carbaldehyde

To a stirred slurry of O-methylisourea hemisulfate (1.08 g, 4.13 mmol),vinamidinium salt (3.00 g, 8.26 mmol), 1-methylethyl acetate (16.0 mL,137 mmol) was added a solution of potassium bicarbonate (1.17 g, 11.6mmol) in water (5.0 mL) over a 10 minutes period. After completion ofthe addition the resulting reaction mixture was stirred at roomtemperature for 40 hours. The mixture was diluted with water (20 mL) andextracted with EtOAc (2×25 mL). The combined organic layers were driedover sodium sulfate and concentrated to yield a white solid.

¹H NMR (300 MHz, CDCl₃) δ: 4.11 (s, 3H), 8.97 (s, 2H), 10.00 (s, 1H).

B) 2-Methoxy-5-vinylpyrimidine

A suspension of methyltriphenylphosphonium bromide (24.8 g, 69.4 mmol)in THF (150 mL) at −78° C. under an atmosphere of nitrogen was added 2.5M of n-butyllithium in hexane (28 mL, 70 mmol) during a period of 12mins. The reaction was warmed to room temperature to yield a deep redylide solution. To the ylide solution, cooled in ice, was introduced2-methoxypyrimidine-5-carbaldehyde (8 g, 65.6 mmol) in THF (50 mL). Thereaction was allowed to reach room temperature and stirred for 3 hours.The result suspension was heated to 60° C. over 30 minutes and thenheated at 60° C. for 1 hour. After cooling, the reaction mixture wasdiluted with water (400 mL) and extracted with EtOAc (2×150 mL). Thecombined organic layers were washed with brine, dried (MgSO₄), andconcentrated. The residue was purified by silica gel chromatography(EtOAc/hexane 0-30%) to yield title compound.

C) (R)-1-(2-Methoxypyrimidin-5-yl)ethane-1,2-diol

A 100 mL flask was charged with tert-butyl alcohol (39 mL), water (39mL), and AD-mix-β (11.0 g). Stirring at room temperature produced twoclear phases; the lower aqueous phase appears bright yellow. The mixturewas cooled to 0° C. whereupon some of the dissolved salts precipitated.2-Methoxy-5-vinylpyrimidine (1.07 g, 7.86 mmol) was added at once, andthe heterogeneous slurry was stirred vigorously at −20° C. forovernight. TLC indicated completion of the reaction. While the mixturewas stirred at 0° C., solid sodium sulfite (12 g, 94 mmol) was added andthe mixture was allowed to warm to rt and stirred for 1 hour. EtOAc (100mL) was added to the reaction mixture, and after separation of thelayers, the aqueous phase was further extracted with EtOAc (2×100 mL).The combined organic layers were dried over anhydrous MgSO₄ andconcentrated in vacuo. The residue was purified by silica gel column(EtOAc/hexane: 50-100%) to yield the diol as a white solid.

D) (R)-2-(tert-Butyldimethylsilyloxy)-1-(2-methoxypyrimidin-5-yl)ethanol

A mixture of (R)-1-(2-methoxypyrimidin-5-yl)ethane-1,2-diol (3.46 g,20.3 mmol) and imidazole (3.08 g, 44.7 mmol) was dissolved in methylenechloride (40 mL). The mixture was cooled to 0° C. andtert-butyldimethylsilyl chloride (3.48 g, 22.4 mmol) dissolved inmethylene chloride (40 mL) was added. The reaction was stirred for 30minutes at 0° C. and then reacted at room temperature overnight. Themixture was treated with water (200 mL) and extracted with methylenechloride (2×200 mL). The combined organic layers were dried over sodiumsulfate and concentrated. The residue was purified by silica gelchromatography (0-50% EtOAc/hexane) to afford a colorless oil.

E)(S)-5-(1-Azido-2-(tert-butyldimethylsilyloxy)ethyl)-2-methoxypyrimidine

A mixture of(R)-2-(tert-butyldimethylsilyloxy)-1-(2-methoxypyrimidin-5-yl)ethanol(4.4 g, 15 mmol) and diphenylphosphonic azide (16.7 mL, 77.3 mmol) wasdissolved in toluene (53 mL). The mixture was cooled to 0° C. and neat1,8-diazabicyclo[5.4.0]undec-7-ene (11.8 mL, 77.3 mmol) was added. Thereaction was stirred for 30 minutes at 0° C. and then reacted at 60° C.overnight. The mixture was washed with water (50 mL) and 5% HCl (50 mL).The organic layer was concentrated in vacuo and purified by silica gelchromatography (0-25% EtOAc/hexane) to afford a colorless oil.

F)(S)-2-(tert-Butyldimethylsilyloxy)-1-(2-methoxypyrimidin-5-yl)ethanamine

A mixture of(S)-5-(1-azido-2-(tert-butyldimethylsilyloxy)ethyl)-2-methoxypyrimidine(11.7 g, 37.7 mmol) in ethyl acetate (300 mL), and 10% Pd—C (70 mg) wasstirred under H₂ (1 atm) overnight. The catalyst was filtered off andthe filtrate was concentrated to yield a light oil. The residue waspurified by silica gel chromatography (0-50% MeOH/EtOAc) to afford acolorless oil.

Intermediates 15 and 16 (S)-1-(2-Methylpyrimidin-5-yl)ethanamine and(R)-1-(2-methylpyrimidin-5-yl)ethanamine

A) 2-methylpyrimidine-5-carbaldehyde

To a stirred slurry of acetamidine hydrochloride (19.4 g, 0.20 mol) andvinamidinium salt (48.91 g, 0.183 mol) in acetonitrile (240 mL) wasadded a solution of 40% wt. NaOH in water (27.4 g, 0.274 mol) over a 30minutes period. After the addition was complete, the resulting reactionmixture was stirred at room temperature overnight. The mixture wasconcentrated in vacuo and diluted with water (250 mL) and extracted withEtOAc (3×250 mL). The combined organic layers were dried over sodiumsulfate and concentrated in vacuo. The residue was purified by silicagel chromatography (0-100% EtOAc/hexanes) to afford a white solid.

B) 1-(2-methylpyrimidin-5-yl)ethanol

To a stirred solution of 2-methylpyrimidine-5-carbaldehyde (5.00 g, 38.9mmol) in tetrahydrofuran (85 mL) was slowly added 33 mL of 1.4 Mmethylmagnesium bromide solution in tetrahydrofuran at 0° C. The mixturewas stirred at room temperature for 1 hour and then quenched with water(50 mL) and extracted with EtOAc (3×200 mL). The combined organic layerswere dried over sodium sulfate and concentrated in vacuo. The residuewas purified by silica gel chromatography (0-100% EtOAc/hexane) toafford a colorless oil.

C) 5-(1-azidoethyl)-2-methylpyrimidine

To a stirred mixture of 1-(2-methylpyrimidin-5-yl)ethanol (2.48 g, 17mmol) and diphenylphosphonic azide (9.3 mL, 41 mmol) in toluene (54.5mL) at 0° C. was added neat 1,8-diazabicyclo[5.4.0]undec-7-ene (6.2 mL,41 mmol). The reaction mixture was stirred at 0° C. for 30 minutes andthen stirred at room temperature overnight. The mixture was diluted withEtOAc (100 mL) and washed with water (100 mL×2). The organic layer wasconcentrated in vacuo and purified by silica gel chromatography (0-100%EtOAc/hexane) to afford a colorless oil.

D) 1-(2-methylpyrimidin-5-yl)ethanamine

A mixture of 5-(1-azidoethyl)-2-methylpyrimidine (2.20 g, 12.8 mmol),ethyl acetate (170 mL), and 10% palladium on carbon (1.32 g) was stirredunder hydrogen (1 atm) overnight. The mixture was filtered andconcentrated. The residue was purified by silica gel column (0-50%MeOH/EtOAc with 10% Et₃N) to afford a colorless oil.

¹H NMR (300 MHz, CD₃OD): δ 8.71 (s, 2H), 4.12 (q, 1H, J=6.6 Hz), 2.67(s, 3H), 1.44 (d, J=6.6 Hz, 3H).

E) (S)-1-(2-methylpyrimidin-5-yl)ethanamine and(R)-1-(2-methylpyrimidin-5-yl)ethanamine

Racemic 1-(2-methylpyrimidin-5-yl)ethanamine (2.78 g, 20.3 mmol) wasresolved by chiral HPLC (sample preparation: sample was dissolved in 4mL EtOH (heated) and 8 mL hexane was added). HPLC conditions: CHIRALPAKAD-H column at 0° C. [ice-bath], 20×250 mm, hexane/EtOH/Et₂NH[85:15:0.03] at 20 mL/min, UV detection at 230 nm) to yield(S)-1-(2-methylpyrimidin-5-yl)ethanamine (1.19 g, >99% ee) and(R)-1-(2-methylpyrimidin-5-yl)ethanamine (1.16 g, >99% ee).

Intermediate 17 (R)-3-Amino-3-(6-methylpyridin-3-yl)propan-1-ol

A) (E)-tert-butyl 3-(6-methylpyridin-3-yl)acrylate

To a solution of 5-bromo-2-methylpyridine (5 g, 29.06 mmol) in NMP (60mL), were added Pd(OAc)₂ (0.325 g, 1.45 mmol) and P(o-tol)₃ (0.883 g,2.9 mmol). Subsequently, a solution of tert-butyl acrylate (13.02 g,101.7 mmol) in Et₃N (16.1 mL, 116.2 mmol) was added under N₂ to theabove mixture and stirred at 90° C. After 16 h, water was added to thereaction mixture and extracted with Et₂O (3×). The combined organicphase was dried over anhydrous Na₂SO₄ and concentrated in vacuo toafford a residue. Purification of the residue by column chromatography(SiO₂, 100-200 mesh, Et₂O/Pet ether 1:9) afforded the title compound.MS: 220 [M+H]⁺;

¹H NMR (300 MHz, CDCl₃): δ 8.6 (s, 1H), 7.7 (d, J=5.8 Hz, 1H), 7.5 (d,J=16.0 Hz, 1H), 7.1 (d, J=8.5 Hz, 1H), 6.4 (d, J=16.0 Hz, 1H), 2.6 (s,3H) and 1.5 (s, 9H).

B) (R)-tert-butyl3-(benzyl((S)-1-phenylethyl)amino)-3-(6-methylpyridin-3-yl)propanoate

To a solution of (S)—N-benzyl-1-phenylethanamine (3.64 g, 17.26 mmol) inTHF (40 mL) at −70° C., was added dropwise n-BuLi (1.6 M, 14.7 mmol)over a period of 30 min and stirred further. After 1 h, a solution of(E)-tert-butyl 3-(6-methylpyridin-3-yl)acrylate (2.7 g, 12.3 mmol) inTHF was added slowly to the above mixture and stirred further. After 2h, sat. NH₄Cl solution was added to the reaction mixture and extractedwith EtOAc (3×). The combined organic phase was dried over anhydrousNa₂SO₄ and concentrated in vacuo to afford a residue. Purification ofthe residue by column chromatography (Neutral Al₂O₃, Et₂O/Pet ether5:95) afforded the title compound.

MS: 431.6 [M+H]⁺;

¹H NMR (300 MHz, CDCl₃): δ 8.5 (dd, J=2 Hz, 1H) 7.2-8.7 (m, 13H), 6.4(d, J=16.0 Hz, 1H), 3.96 (t, J=6.8 Hz, 1H), 3.9 (q, J=6.8 Hz, 1H), 3.6(s, 2H), 2.4-2.6 (m, 5H), 1.6 (s, 2H) and 1.2 (s, 9H).

C)(R)-3-(benzyl((S)-1-phenylethyl)amino)-3-(6-methylpyridin-3-yl)propan-1-ol

To a solution of LiAlH₄ (1.24 g, 32.79 mmol) in THF (80 mL) at 0° C.,was added dropwise a solution of (R)-tert-butyl3-(benzyl((S)-1-phenylethyl)amino)-3-(6-methylpyridin-3-yl)propanoate(4.7 g, 10.93 mmol) in THF and was heated to 75° C. After 4 h, thereaction mixture was quenched with EtOAc and filtered. The filtrate waswashed with excess EtOAc and dried under high vacuum to afford aresidue. Purification of the residue by column chromatography (neutralAl₂O₃, Et₂O/Pet ether 15:85) afforded the title compound.

MS: 361.5 ([M−H]⁺);

¹H NMR (300 MHz, CDCl₃): δ 7.2-8.5 (m, 13H), 4.0-4.1 (m, 2H), 3.4-3.6(m, 3H), 3.3-3.4 (m, 1H), 2.6-2.7 (m, 3H), 2.0-2.2 (m, 3H) and 1.1 (d,J=5.6 Hz, 3H).

D) (R)-3-amino-3-(6-methylpyridin-3-yl)propan-1-ol

To a solution of(R)-3-(benzyl((S)-1-phenylethyl)amino)-3-(6-methylpyridin-3-yl)propan-1-ol(2.1 g, 5.83 mmol) in HPLC MeOH (40 mL), were added AcOH (0.34 mL, 5.8mmol), Pd(OH)₂ (0.42 g) and HCOONH₄ (1.8 g, 29.16 mmol) and was heatedto reflux. After 1 h, the reaction mixture was filtered through a Celitepad and the filtrate was concentrated in vacuo to afford a residue.Purification of the residue by column chromatography (neutral Al₂O₃, aq.NH₃/MeOH/CH₂Cl₂, 1:20:80) afforded the title compound.

¹H-NMR (300 MHz, CDCl₃): δ 7.2-8.4 (m, 3H), 4.2 (t, J=3.6 Hz, 1H), 3.8(t, J=5.1 Hz, 2H), 2.6 (s, 3H), 2.2 (br, 3H) and 1.7-1.8 (m, 2H).

Intermediate 18 (S)-2-Amino-2-(4-(trifluoromethyl)phenyl)ethanol

Lithium tetrahydroaluminate (0.62 g, 0.016 mol) was added slowly, insmall portions, to an ice cooled mixture of4-(trifluoromethyl)-L-phenylglycine (1.8 g, 8.2 mmol) in tetrahydrofuran(60 mL). The mixture was slowly warmed to rt over a period of 1 h andthen heated to reflux overnight. The solution was cooled to 0° C. andquenched with 2.0 M aqueous NaOH solution. The precipitate was filteredoff and the filter cake was washed with THF. The filtrate wasconcentrated and extracted with CH₂Cl₂ (50 mL×3). The combined organiclayers were washed with brine, dried (Na₂SO₄), and concentrated in vacuoto give a light yellow solid (0.9 g, 59%). LC-MS: 206.2 [M+1]⁺.

Intermediates 19 and 20(R)-Cyclopropyl(6-(trifluoromethyl)pyridin-3-yl)methanamine and(S)-cyclopropyl(6-(trifluoromethyl)pyridin-3-yl)methanamine

A) Cyclopropyl(6-(trifluoromethyl)pyridin-3-yl)methanone

To a stirred solution ofN-methoxy-N-methyl-6-(trifluoromethyl)nicotinamide (1.00 g, 4.27 mmol)in tetrahydrofuran (30 mL) at 0° C. was added 0.5 M ofcyclopropylmagnesium bromide in tetrahydrofuran (20 mL, 0.01 mol)dropwise over 15 minutes. The mixture was stirred at 0° C. for 30minutes then at room temperature overnight. The reaction was quenchedwith 1N HCl. Solvent was removed and the aqueous layer was extractedwith ethyl acetate. Thr organic layers were combined and dried withMgSO₄, filtered and concentrated. The crude product was purified bysilica gel column (0-60% ethyl acetate/hexane) to obtain a pale yellowsolid.

B)(R)—N—((R)-Cyclopropyl(6-(trifluoromethyl)pyridin-3-yl)methyl)-2-methylpropane-2-sulfinamideand(R)—N—((S)-cyclopropyl(6-(trifluoromethyl)pyridin-3-yl)methyl)-2-methylpropane-2-sulfinamide

To a stirred solution of Ti(OEt)₄ (1.1 mL, 5.5 mmol) andcyclopropyl(6-(trifluoromethyl)pyridin-3-yl)methanone (0.84 g, 3.9 mmol)in tetrahydrofuran (20 mL) under N₂ was added(R)-2-methylpropane-2-sulfinamide (0.57 g, 4.7 mmol). The mixture washeated to 70° C. and heated overnight. The mixture was cooled to roomtemperature and then to −78° C. and cannulated slowly into a −78° C.solution of sodium tetrahydroborate (0.49 g, 13 mmol) in 20 mL of THF.The reaction was slowly warmed to room temperature and stirredovernight, and then quenched with methanol. The solution was filteredthrough Celite and the filter cake was washed with ethyl acetate. Thefiltrate was washed with brine, dried (Na₂SO₄), filtered, andconcentrated. NMR showed about 10% S-isomer in the crude material (0.77g, 62%). The diastereomers were seperated by silica gel column (0-80%ethyl acetate/hexane). R,R-isomer (major) is less polar, whileR,S-isomer is more polar.

C) (R)-Cyclopropyl(6-(trifluoromethyl)pyridin-3-yl)methanamine

(R)—N—((R)-Cyclopropyl(6-(trifluoromethyl)pyridin-3-yl)methyl)-2-methylpropane-2-sulfinamide(0.245 g, 0.000765 mol), ethanol (2.7 g, 0.059 mol), and 4.0 M ofhydrogen chloride in dioxane (2.7 mL, 0.011 mol) were combined andstirred overnight. Reaction was concentrated to down to oil and thenredissolved and washed with ethanol for 3 times, and concentrated. Theresidue was dried on the high vacuum overnight to obtain the titlecompound.

D) (S)-Cyclopropyl(6-(trifluoromethyl)pyridin-3-yl)methanamine

(S)—N—((R)-cyclopropyl(6-(trifluoromethyl)pyridin-3-yl)methyl)-2-methylpropane-2-sulfinamide(0.245 g, 0.000765 mol), ethanol (2.7 g, 0.059 mol), and 4.0 M ofhydrogen chloride in dioxane (2.7 mL, 0.011 mol) are combined andstirred for 30 minutes. The mixture is allowed to stir overnight. Thesolvent is removed and the residue is dissolved in ethanol. Afterwashing with ethanol for 3 times, the mixture is concentrated and theresidue is dried under high vacuum overnight to obtain the titlecompound.

Intermediate 21 Quinolin-7-ylmethanamine

A) 7-(Trifluoromethyl)quinoline

4-Chloro-7-(trifluoromethyl)quinoline (9.35 g, 0.0404 mol) washydrogenated in the presence of 5% palladium on carbon (4 g) in methanol(180 mL) in the presence of triethylamine (6 mL). The solution wasstirred for 3.5 hours, and then filtered through Celite. The filtratewas concentrated under reduced pressure, and the residue was treatedwith ethyl acetate and water. The organic layer was separated, washedwith water (2×75 mL), dried over MgSO₄, filtered, and concentrated underreduced pressure to a yellow solid.

B) Methyl quinoline-7-carboxylate

7-(Trifluoromethyl)quinoline (1 g, 5 mmol) was dissolved in 80% oleum(80:20, sulfuric acid:water, 50 mL), and the mixture was heated to 150°C. overnight. The solution was cooled to 0° C. and methanol (50 mL) wasadded slowly and the mixture was refluxed overnight. After cooling, themixture was concentrated under reduced pressure to an oil andneutralized with saturated aqueous Na₂CO₃, and extracted with EtOAc (30mL×3). The combined organic layers was dried with MgSO₄, andconcentrated. The residue was purified by silica gel column to affordthe title compound.

C) quinolin-7-ylmethanol

Methyl quinoline-7-carboxylate (5 g, 0.01 mol) was dissolved intetrahydrofuran (40 mL) at −20° C. under an atmosphere of nitrogen. 60%REDAL (60:40, Red-Al(R):toluene, 6.53 mL, 0.0201 mol) was added andallowed to stir at −20° C. for 4 hours. After warming to roomtemperature, the reaction was quenched slowly with water, concentratedunder reduced pressure, partitioned between EtOAc and water, andfiltered through Celite. The aqueous phase was extracted with EtOAc. Thecombined organic layers were dried with MgSO₄, and concentrated underreduced pressure. The residue was purified by silica gel column toafford the title compound.

D) 7-(Azidomethyl)quinoline

A mixture of quinolin-7-ylmethanol (1.2 g, 7.2 mmol) anddiphenylphosphonic azide (3.8 mL, 17 mmol) was dissolved in toluene (20mL) and methylene chloride (6 mL). The mixture was cooled to 0° C. andneat 1,8-diazabicyclo[5.4.0]undec-7-ene (2.6 mL, 17 mmol) was added. Thereaction was stirred for 30 minutes at 0° C. and then reacted at roomtemperature for 2 h. The mixture was diluted with CH₂Cl₂ (100 mL) andwashed with water (100 mL×2). The organic layer was concentrated invacuo and purified by silica gel chromatography (0-100% EtOAc/hexane) toafford a colorless oil.

E) Quinolin-7-ylmethanamine

7-(Azidomethyl)quinoline (1.1 g, 5.7 mmol) was hydrogenated (1 atm) inthe presence of Raney nickel (1.5 g, 26 mmol) in methanol (30 mL) untilcompletion of the reaction. Catalyst was filtered off and the filtratewas concentrated under reduced pressure to a yellow oil which wasdissolved in EtOAc (32 mL) and extracted with 1N hydrochloric acid (3×32mL). The combined acidic aqueous phases were adjust to pH˜10 with 1Nsodium hydroxide solution, and extracted with EtOAc (3×35 mL). Thecombined organic layers were dried over MgSO₄, filtered, andconcentrated under reduced pressure to afford a white solid (0.89 g,94%).

¹H NMR (300 MHz, CD₃OD) 8.83 (d, J=4.2 Hz, 1H), 8.36 (d, J=7.8 Hz, 1H),7.97 (s, 1H), 7.94 (d, J=8.4 Hz, 1H), 7.64 (d, J=8.4 Hz, 1H), 7.52 (dd,J=7.8, 4.2 Hz, 1H), 4.05 (s, 2H).

Representative Methods Method A Compound 15-Methyl-2-{4-[(6-trifluoromethyl-pyridin-3-ylmethyl)-amino]-7,8-dihydro-5H-pyrido[4,3-d]pyrimidin-6-yl}-benzonitrile

A)6-Benzyl-N-((6-(trifluoromethyl)pyridin-3-yl)methyl)-5,6,7,8-tetrahydropyrido[4,3-d]pyrimidin-4-amine

Two 20 mL microwave vials were each charged with a half portion of6-benzyl-4-chloro-5,6,7,8-tetrahydropyrido[4,3-d]pyrimidine (5.62 g,21.6 mmol), (6-(trifluoromethyl)pyridin-3-yl)methanamine (5.0 g, 28mmol), N,N-diisopropylethylamine (7.6 mL, 44 mmol) and acetonitrile (10mL), and the mixture was subjected to a microwave irradiation at 200° C.for 3.5 h. LC-MS analysis showed the reaction was complete for bothsamples. The samples were combined, and partitioned between CH₂Cl₂ (150mL) and 0.5M NaH₂PO₄ (pH 4; 120 mL). The organic layer was extractedwith 2M HCl (60 mL, 30 mL). The combined acid extracts were basifiedwith 50% KOH (25 mL), extracted with CH₂Cl₂ (2×100 mL), dried (Na₂SO₄),filtered and concentrated to yield a light brown oil, which was absorbedon silica (40 g) and purified by column (120 g silica gel, 0-7.5%MeOH/CH₂Cl₂) to afford a light yellow foam (7.42 g, 86%).

LC-MS: 400.4 [M+H]⁺

¹H NMR (400 MHz, CDCl₃): δ 8.67 (d, 1H, J=1.8 Hz), 8.45 (s, 1H), 7.83(dd, 1H, J=8.0, 1.8 Hz), 7.62 (d, 1H, J=7.9 Hz), 7.39-7.27 (m, 5H), 4.79(s, 2H), 3.77 (s, 2H), 3.31 (s, 2H), 2.90-2.80 (m, 4H).

B)N-((6-(Trifluoromethyl)pyridin-3-yl)methyl)-5,6,7,8-tetrahydropyrido[4,3-d]pyrimidin-4-amine

A mixture of6-benzyl-N-((6-(trifluoromethyl)pyridin-3-yl)methyl)-5,6,7,8-tetrahydropyrido[4,3-d]pyrimidin-4-amine(7.41 g, 18.6 mmol), methanol (300 mL), and 10% palladium on charcoal(1.0 g) was evacuated and purged with hydrogen 3 times, thenhydrogenated (1 atm) at room temperature for 2 days. The mixture wasfiltered through a pad of Celite and the filter cake was washed withMeOH. The filtrate was concentrated in vacuo to yield a pale yellow foam(4.8 g). LC-MS: 310.4 [M+H]⁺

C)5-Bromo-2-(4-((6-(trifluoromethyl)pyridin-3-yl)methylamino)-7,8-dihydropyrido[4,3-d]pyrimidin-6(5H)-yl)benzonitrile

A mixture ofN-((6-(trifluoromethyl)pyridin-3-yl)methyl)-5,6,7,8-tetrahydropyrido[4,3-d]pyrimidin-4-amine(1.0 g, 3.2 mmol), 5-bromo-2-fluorobenzonitrile (0.97 g, 4.8 mmol),N,N-diisopropylethylamine (1.7 mL, 9.7 mmol), and acetonitrile (10 mL)was subjected to microwave irradiation at 180° C. for 2 h. More5-bromo-2-fluorobenzonitrile (1.0 g) was added and the mixture wassubjected to microwave irradiation at 180° C. for another 2 h. Thenadditional 5-bromo-2-fluorobenzonitrile (1.0 g) was added and thereaction mixture was subjected to microwave irradiation at 180° C. foran additional 2 h. After cooling, the mixture was diluted with EtOAc(100 mL) and washed with aq. Na₂CO₃ solution and brine, dried (Na₂SO₄)and concentrated. The residue was purified by silica gel column (100%EtOAc) to yield a light yellow solid (0.90 g, 57%).

LC-MS: 491.1 [M+H]⁺

¹H NMR (400 MHz, d6-DMSO): δ 8.76 (s, 1H), 8.30 (s, 1H), 8.03 (d, 1H,J=2.4 Hz), 7.99 (d, 1H, J=8.8 Hz), 7.88 (dd, 1H, J=8.8, 2.4 Hz), 7.84(d, 1H, J=8.0 Hz), 7.64 (t, 1H, J=5.6 Hz), 7.25 (d, 1H, J=8.8 Hz), 4.76(d, 2H, J=5.6 Hz), 4.08 (s, 2H), 3.59 (t, 2H, J=5.6 Hz), 2.87 (t, 2H,J=5.6 Hz).

D)5-Methyl-2-(4-((6-(trifluoromethyl)pyridin-3-yl)methylamino)-7,8-dihydropyrido[4,3-d]pyrimidin-6(5H)-yl)benzonitrile

To a mixture of5-bromo-2-(4-((6-(trifluoromethyl)pyridin-3-yl)methylamino)-7,8-dihydropyrido[4,3-d]pyrimidin-6(5H)-yl)benzonitrile(120 mg, 0.24 mmol), methylboronic acid (19 mg, 0.32 mmol), potassiumphosphate (182 mg, 0.86 mmol), tricyclohexylphosphine (6.9 mg, 0.024mmol), toluene (5 mL), and water (0.5 mL) under argon was addedpalladium acetate (2.8 mg, 0.012 mmol). The mixture was heated at 100°C. for 20 h and then cooled to rt. The mixture was filtered andconcentrated. The residue was purified by semi-preparative HPLC to yieldan off-white solid (75 mg, 71%).

LC-MS: 425.1 [M+H]⁺

¹H NMR (400 MHz, d6-DMSO): δ 8.75 (s, 1H), 8.29 (s, 1H), 7.98 (d, 1H,J=8.0 Hz), 7.84 (d, 1H, J=8.0 Hz), 7.61 (t, 1H, J=5.6 Hz), 7.59 (d, 1H,J=1.6 Hz), 7.50 (dd, 1H, J=8.4, 1.6 Hz), 7.24 (d, 1H, J=8.4 Hz), 4.75(d, 2H, J=5.6 Hz), 4.04 (s, 2H), 3.50 (t, 2H, J=5.6 Hz), 2.85 (t, 2H,J=5.6 Hz), 2.29 (s, 3H).

Method B Compound 35-Cyclopropyl-2-{4-[(6-trifluoromethyl-pyridin-3-ylmethyl)-amino]-7,8-dihydro-5H-pyrido[4,3-d]pyrimidin-6-yl}-benzonitrile

To a mixture of5-bromo-2-(4-((6-(trifluoromethyl)pyridin-3-yl)methylamino)-7,8-dihydropyrido[4,3-d]pyrimidin-6(5H)-yl)benzonitrile(13 mg, 0.026 mmol), cyclopropylboronic acid (3.0 mg, 0.034 mmol),potassium phosphate (20 mg, 0.093 mmol), tricyclohexylphosphine (2.5 mg,0.0090 mmol), toluene (2.0 mL), and water (0.04 mL) under argon wasadded palladium acetate (1.0 mg, 0.0044 mmol). The mixture was heated at100° C. for 3 h and then cooled to rt. Water (10 mL) and EtOAc (100 mL)were added. The organic layer was separated and washed with brine, dried(Na₂SO₄), and concentrated. The residue was purified by semi-preparativeHPLC to yield a white solid (7 mg, 58%).

LC-MS: 451.0 [M+H]⁺

¹H NMR (400 MHz, d6-DMSO): δ 8.75 (s, 1H), 8.29 (s, 1H), 7.98 (d, 1H,J=8.0 Hz), 7.84 (d, 1H, J=8.0 Hz), 7.61 (t, 1H, J=5.6 Hz), 7.48 (d, 1H,J=2.4 Hz), 7.40 (dd, 1H, J=8.4, 2.4 Hz), 7.22 (d, 1H, J=8.4 Hz), 4.75(d, 2H, J=5.6 Hz), 4.03 (s, 2H), 3.49 (t, 2H, J=5.6 Hz), 2.85 (t, 2H,J=5.6 Hz), 1.94 (m, 1H), 0.94 (m, 2H), 0.70 (m, 2H).

Method C Compound 45-Chloro-2-{4-[(6-trifluoromethyl-pyridin-3-ylmethyl)-amino]-7,8-dihydro-5H-pyrido[4,3-d]pyrimidin-6-yl}-benzonitrile

A 2 mL microwave vial was charged withN-((6-(trifluoromethyl)pyridin-3-yl)methyl)-5,6,7,8-tetrahydropyrido[4,3-d]pyrimidin-4-amine(50 mg, 0.16 mmol), 5-chloro-2-fluorobenzonitrile (150 mg, 0.97 mmol),acetonitrile (0.4 mL), and N,N-diisopropylethylamine (84 μL, 0.48 mmol).The mixture was subjected to a microwave irradiation at 200° C. for 2 h.The mixture was diluted with chloroform (7 mL), and washed with 0.1 MNaH₂PO₄ (10 mL), dried (Na₂SO₄), filtered and concentrated. The residuewas purified by silica gel column to yield a light yellow solid (32 mg).

LC-MS: 445.3[M+H]⁺

¹H NMR (400 MHz, d6-DMSO): δ 8.76 (s, 1H), 8.30 (s, 1H), 7.99 (dd, 1H,J=8.0, 1.6 Hz), 7.94 (d, 1H, J=2.8 Hz), 7.84 (d, 1H, J=8.0 Hz), 7.77(dd, 1H, J=8.8, 2.8 Hz), 7.63 (t, 1H, J=5.6 Hz), 7.31 (d, 1H, J=8.8 Hz),4.76 (d, 2H, J=5.6 Hz), 4.09 (s, 2H), 3.59 (t, 2H, J=5.6 Hz), 2.87 (t,2H, J=5.6 Hz).

Method D Compound 55-Trifluoromethyl-2-{4-[(6-trifluoromethyl-pyridin-3-ylmethyl)-amino]-7,8-dihydro-5H-pyrido[4,3-d]pyrimidin-6-yl}-benzonitrile

A 2 mL microwave vial was charged withN-((6-(trifluoromethyl)pyridin-3-yl)methyl)-5,6,7,8-tetrahydropyrido[4,3-d]pyrimidin-4-amine(40 mg, 0.13 mmol), 2-fluoro-5-(trifluoromethyl)benzonitrile (150 mg,0.78 mmol), acetonitrile (0.4 mL) and N,N-diisopropylethylamine (68 μL,0.39 mmol). The mixture was subjected to microwave irradiation at 200°C. for 2 h. The mixture was diluted with chloroform (7 mL), and washedwith 0.1 M NaH₂PO₄ (10 mL), dried (Na₂SO₄), filtered and concentrated.The residue was purified by silica gel column to yield a pale brownsolid.

LC-MS: 479.3 [M+H]⁺

¹H NMR (400 MHz, CD₃OD): δ 8.72 (s, 1H), 8.33 (s, 1H), 8.02 (d, 1H,J=8.0 Hz), 7.98 (d, 1H, J=2.0 Hz), 7.86 (dd, 1H, J=8.8, 2.0 Hz), 7.76(d, 1H, J=8.0 Hz), 7.40 (d, 1H, J=8.8 Hz), 4.86 (s, 2H), 4.23 (s, 2H),3.80 (t, 2H, J=5.6 Hz), 3.02 (t, 2H, J=5.6 Hz).

Method E Compound 75-Methyl-2-{4-[(R)-1-(6-trifluoromethyl-pyridin-3-yl)-ethylamino]-7,8-dihydro-5H-pyrido[4,3-d]pyrimidin-6-yl}-benzonitrile

A)(R)-5-Bromo-2-(4-(1-(6-(trifluoromethyl)pyridin-3-yl)ethylamino)-7,8-dihydropyrido[4,3-d]pyrimidin-6(5H)-yl)benzonitrile

A mixture of(R)—N-(1-(6-(trifluoromethyl)pyridin-3-yl)ethyl)-5,6,7,8-tetrahydropyrido[4,3-d]pyrimidin-4-amine(300 mg, 0.93 mmol), 5-bromo-2-fluorobenzonitrile (560 mg, 2.8 mmol),N,N-diisopropylethylamine (480 μL, 2.8 mmol), and acetonitrile (4 mL)was subjected to microwave irradiation at 180° C. for 2 h. More5-bromo-2-fluorobenzonitrile (500 mg) was added and the mixture wassubjected to microwave irradiation at 180° C. for another 2 h.Additional 5-bromo-2-fluorobenzonitrile (500 mg) was added and themixture was subjected to microwave irradiation at 180° C. for anadditional 2 h. LC-MS indicated the amine was nearly completelyconsumed. After cooling the mixture was concentrated in vacuo, and theresidue was purified by silica gel column (100% EtOAc) to yield a lightyellow solid (255 mg, 54%).

LC-MS: 505.0 [M+H]⁺

¹H NMR (400 MHz, d6-DMSO): δ 8.82 (s, 1H), 8.25 (s, 1H), 8.07-8.04 (m,2H), 7.89 (dd, 1H, J=8.8, 2.4 Hz), 7.84 (d, 1H, J=8.0 Hz), 7.33 (d, 1H,J=8.8 Hz), 7.24 (d, 1H, J=7.2 Hz), 5.50 (m, 1H), 4.17 and 4.07 (AB, 2H,J=15.6 Hz), 3.56 (m, 2H), 2.86 (t, 2H, J=5.6 Hz), 1.58 (d, 3H, J=7.2Hz).

B)(R)-5-Methyl-2-(4-(1-(6-(trifluoromethyl)pyridin-3-yl)ethylamino)-7,8-dihydropyrido[4,3-d]pyrimidin-6(5H)-yl)benzonitrile

To a mixture of(R)-5-bromo-2-(4-(1-(6-(trifluoromethyl)pyridin-3-yl)ethylamino)-7,8-dihydropyrido[4,3-d]pyrimidin-6(5H)-yl)benzonitrile(240 mg, 0.48 mmol), methylboronic acid (37.0 mg, 0.619 mmol), potassiumphosphate (354 mg, 1.67 mmol), tricyclohexylphosphine (25 mg, 0.089mmol), toluene (10 mL), and water (0.6 mL) under argon was addedpalladium acetate (10 mg, 0.04 mmol). The mixture was heated at 100° C.for 3 h and then cooled to rt. The mixture was filtered andconcentrated. The residue was purified by semi-preparative HPLC to yielda light yellow solid (145 mg, 69%).

LC-MS: 439.2 [M+H]⁺

¹H NMR (400 MHz, d6-DMSO): δ 8.81 (d, 1H, J=2.0 Hz), 8.24 (s, 1H), 8.05(dd, 1H, J=8.0, 2.0 Hz), 7.84 (d, 1H, J=8.0 Hz), 7.60 (d, 1H, J=1.6 Hz),7.52 (dd, 1H, J=8.4, 1.6 Hz), 7.31 (d, 1H, J=8.4 Hz), 7.22 (d, 1H, J=7.2Hz), 5.50 (m, 1H), 4.13 and 4.03 (AB, 2H, J=15.6 Hz), 3.48 (m, 2H), 2.84(t, 2H, J=5.6 Hz), 2.30 (s, 3H), 1.58 (d, 3H, J=7.2 Hz).

Method F Compound 8(R)-5-Chloro-2-(4-(1-(6-(trifluoromethyl)pyridin-3-yl)ethylamino)-7,8-dihydropyrido[4,3-d]pyrimidin-6(5H)-yl)benzonitrile

A)(R)-6-Benzyl-N-(1-(6-(trifluoromethyl)pyridin-3-yl)ethyl)-5,6,7,8-tetrahydropyrido[4,3-d]pyrimidin-4-amine

6-Benzyl-4-chloro-5,6,7,8-tetrahydropyrido[4,3-d]pyrimidine (5.00 g,19.2 mmol), (R)-1-(6-(trifluoromethyl)pyridin-3-yl)ethanamine (4.76 g,25.0 mmol), N,N-diisopropylethylamine (6.71 mL, 38.5 mmol), andacetonitrile (15 mL) were divided evenly between two 20 mL microwavevials. The reactions were subjected to microwave irradiation at 200° C.for 3.5 h. The two reactions were mixed together and evaporated theacetonitrile off. The residue was redissolved in CH₂Cl₂ (150 mL) andwashed with 1M NaH₂PO₄ (2×50 mL). The product was extracted with 1M HCl(2×50 mL). The aqueous extracts were basified to pH 14 and extractedwith CH₂Cl₂ (2×50 mL). The combined organic layers were dried withNa₂SO₄, filtered and evaporated to produce a yellow to orange solid(7.21 g). The crude product was washed with ether (25 mL) by stirringthe solids for about 30 minutes. The solids were filtered from the etherand washed with ether (2×5 mL) to obtain a pale yellow powder (3.55 g,45% yield). The ether filtrate was absorbed onto silica and purified bycolumn with MeOH/CH₂Cl₂ (0-10%) to yield more product (2.38 g, 30%yield; 75% combined yield).

LC-MS: 414.5 [M+H]⁺

¹H NMR (400 MHz, CDCl₃): δ 8.72 (d, 1H, J=1.6 Hz), 8.37 (s, 1H), 7.80(dd, 1H, J=8.4, 1.6 Hz), 7.62 (d, 1H, J=8.0 Hz), 7.42-7.28 (m, 5H), 5.47(m, 1H), 4.43 (d, 1H, J=6.4 Hz), 3.79 and 3.75 (AB, 2H, J=13.2 Hz), 3.37(t, 2H, J=14.8 Hz), 2.88-2.76 (m, 4H), 1.62 (d, 3H, J=6.8 Hz).

B)(R)—N-(1-(6-(Trifluoromethyl)pyridin-3-yl)ethyl)-5,6,7,8-tetrahydropyrido[4,3-d]pyrimidin-4-amine

A mixture of(R)-6-benzyl-N-(1-(6-(trifluoromethyl)pyridin-3-yl)ethyl)-5,6,7,8-tetrahydropyrido[4,3-d]pyrimidin-4-amine(3.55 g, 8.59 mmol), 10% palladium on charcoal (740 mg), and methanol(60 mL) were stirred under hydrogen (1 atm) for 15 h. The catalyst wasfiltered off through Celite and the filter cake was washed with MeOH(3×30 mL). The filtrate was concentrated to obtain an off-white foam(2.74 g, 98% yield).

LC-MS: 324.5 [M+H]⁺;

¹H NMR (400 MHz, CDCl₃): δ 8.74 (d, 1H, J=1.6 Hz), 8.37 (s, 1H), 7.83(dd, 1H, J=8.0, 1.6 Hz), 7.63 (d, 1H, J=8.0 Hz), 5.48 (m, 1H), 4.55 (d,1H, J=6.8 Hz), 3.74 (s, 2H), 3.17 (t, 2H, J=6.0 Hz), 2.75 (t, 2H, J=6.0Hz), 1.64 (d, 3H, J=6.8 Hz).

C)(R)-5-Chloro-2-(4-(1-(6-(trifluoromethyl)pyridin-3-yl)ethylamino)-7,8-dihydropyrido[4,3-d]pyrimidin-6(5H)-yl)benzonitrile

A mixture of(R)—N-(1-(6-(trifluoromethyl)pyridin-3-yl)ethyl)-5,6,7,8-tetrahydropyrido[4,3-d]pyrimidin-4-amine(500 mg, 1.55 mmol), 5-chloro-2-fluorobenzonitrile (360 mg, 2.3 mmol),N,N-diisopropylethylamine (540 μL, 3.1 mmol), and acetonitrile (3.0 mL)was subjected to microwave irradiation at 180° C. for 2 h. Then more5-chloro-2-fluorobenzonitrile (360 mg) was added and the mixture wassubjected to microwave irradiation at 180° C. for another 2 h. Afterthat an additional 5-chloro-2-fluorobenzonitrile (360 mg) was added andthe mixture was subjected to microwave irradiation at 180° C. for anadditional 2 h. After cooling the mixture was concentrated in vacuo andthe residue was purified by silica gel column (0-100% EtOAc/hexane) andthe obtained solid was washed with ether to yield an off-white solid(370 mg, 51%).

LC-MS: 459.1[M+H]⁺

¹H NMR (400 MHz, d6-DMSO): δ 8.82 (d, 1H, J=2.0 Hz), 8.25 (s, 1H), 8.05(dd, 1H, J=8.0, 2.0 Hz), 7.95 (d, 1H, J=2.4 Hz), 7.84 (d, 1H, J=8.0 Hz),7.79 (dd, 1H, J=8.8, 2.4 Hz), 7.40 (d, 1H, J=8.8 Hz), 7.24 (d, 1H, J=7.2Hz), 5.50 (m, 1H), 4.18 and 4.08 (AB, 2H, J=15.6 Hz), 3.57 (m, 2H), 2.86(t, 2H, J=5.6 Hz), 1.58 (d, 3H, J=7.2 Hz).

Method G Compound 95-Fluoro-2-{4-[(6-trifluoromethyl-pyridin-3-ylmethyl)-amino]-7,8-dihydro-5H-pyrido[4,3-d]pyrimidin-6-yl}-benzonitrile

A 2 mL microwave vial was charged withN-((6-(trifluoromethyl)pyridin-3-yl)methyl)-5,6,7,8-tetrahydropyrido[4,3-d]pyrimidin-4-amine(50 mg, 0.16 mmol), 2,5-difluorobenzonitrile (130 mg, 0.97 mmol),acetonitrile (0.4 mL) and N,N-diisopropylethylamine (84 μL, 0.48 mmol).The mixture was subjected to microwave irradiation at 200° C. for 4 h.After cooling the mixture was diluted with chloroform (7 mL), and washedwith 0.1 M NaH₂PO₄ (10 mL), dried (Na₂SO₄), filtered and concentrated.The residue was purified by semi-preparative HPLC (100×20.2 mm, C18column; 20-90% MeCN/H₂O [10 mM diethylamine]) to yield an off-whitesolid (8 mg).

LC-MS: 429.6 [M+H]⁺

¹H NMR (400 MHz, CD₃OD): δ 8.70 (s, 1H), 8.32 (s, 1H), 8.00 (d, 1H,J=8.0 Hz), 7.75 (d, 1H, J=8.0 Hz), 7.51 (dd, 1H, J=8.0, 2.8 Hz),7.45-7.39 (m, 1H), 7.34 (dd, 1H, J=9.2, 4.8 Hz), 4.84 (s, 2H), 4.08 (s,2H), 3.56 (t, 2H, J=5.6 Hz), 2.98 (t, 2H, J=5.6 Hz).

Method H Compound 115-Chloro-2-(4-((2-methyl-6-(trifluoromethyl)pyridin-3-yl)methylamino)-7,8-dihydropyrido[4,3-d]pyrimidin-6(5H)-yl)benzonitrile

A) 3-(Azidomethyl)-2-methyl-6-(trifluoromethyl)pyridine

A 25 mL flask was charged with(2-methyl-6-(trifluoromethyl)pyridin-3-yl)methanol (287 mg, 1.50 mmol),tetrahydrofuran (5 mL) and diphenylphosphonic azide (356 μL, 1.65 mmol),purged with nitrogen, and cooled in ice. A solution of1,8-diazabicyclo[5.4.0]undec-7-ene (236 μL, 1.57 mmol) in THF (1 mL) wasadded dropwise to the resultant mixture, and after 1.5 h, the mixturewas warmed to room temperature and stirred overnight. Additionaldiphenylphosphonic azide (100 μL, 0.3 equiv.) was added followed byadditional 1,8-diazabicyclo[5.4.0]undec-7-ene (90 μL, 0.4 equiv.), andthe mixture was again stirred overnight. The reaction was quenched with1M NaOH (20 mL), and poured into chloroform (20 mL). The organic layerwas washed with 1M Na₂HPO₄ (pH 8, 2×15 mL), dried (Na₂SO₄), filtered andconcentrated to a yellow oil which was purified by silica gel column(0-25% ethyl acetate/hexane) to yield a colorless oil (301 mg, 93%).

B) (2-Methyl-6-(trifluoromethyl)pyridin-3-yl)methanamine

To a stirred solution of3-(azidomethyl)-2-methyl-6-(trifluoromethyl)pyridine (292 mg, 1.35 mmol)in tetrahydrofuran (5 mL) was added triphenylphosphine (710 mg, 2.7mmol), and the mixture was stirred to dissolution. After 5 min themixture was placed in an oil bath at 50° C. and stirred overnight. Themixture was hydrolyzed with 2M HCl (3 mL) for 0.5 h, then partitionedbetween ethyl acetate (30 mL) and 0.5 M NaH₂PO₄ (30 mL). The organicphase was extracted with 0.5 M NaH₂PO₄ (10 mL), and the combined acidicaqueous extracts were basified with 50% KOH, and extracted with CH₂Cl₂(2×30 mL). The combined CH₂Cl₂ layers were dried (Na₂SO₄), filtered andconcentrated to a faintly yellow semi-solid (0.53 g). NMR and LC-MSshowed that the material was only partially cleaved to the free amine(40%) with the remaining 60% being the phospinimine. The mixture wasdissolved in MeOH (10 mL) and heated at reflux for 2 h. The mixture wasconcentrated in vacuo and the residue was treated with water (10 mL) and6N HCl to pH<1, and ether (20 mL). The aqueous phase was separated andextracted with ether (20 mL). The aqueous layer was adjusted to pH>13with 2N aq. KOH and extracted with CH₂Cl₂ (3×50 mL). The combinedorganic layers were washed with brine, dried (Na₂SO₄), and concentratedto yield an oil which was used for the next step reaction withoutfurther purification.

LC-MS: 191.0 [M+H]⁺; ¹H NMR (400 MHz, d6-DMSO): δ 8.01 (d, 1H, J=8.0Hz), 7.70 (d, 1H, J=8.0 Hz), 3.80 (s, 2H), 2.5 (s, 3H), 1.95 (bs, 2H).

C)5-Chloro-2-(4-((2-methyl-6-(trifluoromethyl)pyridin-3-yl)methylamino)-7,8-dihydropyrido[4,3-d]pyrimidin-6(5H)-yl)benzonitrile

A mixture of 2-methyl-6-(trifluoromethyl)pyridin-3-yl)methanamine (39.2mg, 0.206 mmol),2-(4-bromo-7,8-dihydropyrido[4,3-d]pyrimidin-6(5H)-yl)-5-chlorobenzonitrile(60 mg, 0.17 mmol), N,N-diisopropylethylamine (60 μL, 0.34 mmol) inacetonitrile (2.2 mL) was subjected to microwave irradiation at 180° C.for 6 hours. The reaction mixture was concentrated down to an oil andpurified by semi-preparative HPLC (100×20.2 mm, C18 column; 20-80%CH₃CN-water [10 mM Et₂NH) to obtain a white solid (35 mg).

LC-MS: 459.0 [M+H]⁺

¹H NMR (400 MHz, d6-DMSO): δ 8.29 (s, 1H), 7.94 (d, 1H, J=2.8 Hz), 7.80(d, 1H, J=8.4 Hz), 7.77 (dd, 1H, J=8.8, 2.8 Hz), 7.64 (d, 1H, J=8.0 Hz),7.54 (t, 1H, J=5.6 Hz), 7.33 (d, 1H, J=8.8 Hz), 4.70 (d, 2H, J=5.6 Hz),4.11 (s, 2H), 3.60 (t, 2H, J=5.6 Hz), 2.88 (t, 2H, J=5.6 Hz), 2.61 (s,3H).

Method I Compound 125-Chloro-2-(4-((6-(dimethylamino)pyridin-3-yl)methylamino)-7,8-dihydropyrido[4,3-d]pyrimidin-6(5H)-yl)benzonitrile

A mixture of 5-(aminomethyl)-N,N-dimethylpyridin-2-amine (24 mg, 0.16mmol),2-(4-bromo-7,8-dihydropyrido[4,3-d]pyrimidin-6(5H)-yl)-5-chlorobenzonitrile(50 mg, 0.14 mmol), and N,N-diisopropylethylamine (62 μL, 0.36 mmol) inacetonitrile (1.9 mL) was subjected to microwave irradiation at 180° C.for 6 hrs. The reaction mixture was concentrated to an oil which waspurified by silica gel column (0-15% MeOH/CH₂Cl₂) to obtain a lightyellow solid.

LC-MS: 420.5 [M+H]⁺

¹H NMR (400 MHz, d6-DMSO): δ 8.33 (s, 1H), 8.07 (d, 1H, J=2.0 Hz), 7.93(d, 1H, J=2.4 Hz), 7.75 (dd, 1H, J=8.8, 2.8 Hz), 7.49 (dd, 1H, J=8.4,2.4 Hz), 7.35 (br, 1H), 7.31 (d, 1H, J=8.8 Hz), 6.58 (d, 1H, J=8.8 Hz),4.49 (d, 2H, J=5.6 Hz), 3.99 (s, 2H), 3.56 (t, 2H, J=5.6 Hz), 2.97 (s,6H), 2.84 (t, 2H, J=5.6 Hz).

Method J Compound 135-Chloro-2-(4-((6-methoxypyridin-3-yl)methylamino)-7,8-dihydropyrido[4,3-d]pyrimidin-6(5H)-yl)benzonitrile

A)6-Benzyl-N-((6-chloropyridin-3-yl)methyl)-5,6,7,8-tetrahydropyrido[4,3-d]pyrimidin-4-amine

A mixture of 6-benzyl-4-chloro-5,6,7,8-tetrahydropyrido[4,3-d]pyrimidine(2.5 g, 9.6 mmol), 2-chloro-5-aminomethylpyridine (2.7 g, 19 mmol),acetonitrile (10 mL), and N,N-diisopropylethylamine (3.4 mL, 19 mmol)was subjected to microwave irradiation at 180° C. for 2 h. Afterstanding at rt overnight, the precipitated solids were collected byfiltration and washed with cold acetonitrile (5 mL×2), and dried toyield a yellow powder (2.8 g, 77%).

LC-MS: 366.3 [M+H]⁺

¹H NMR (400 MHz, d6-DMSO): δ 8.34 (d, 1H, J=2.8 Hz), 8.23 (s, 1H), 7.74(dd, 1H, J=8.4, 2.8 Hz), 7.45-7.25 (m, 7H), 4.56 (d, 2H, J=6.0 Hz), 3.72(s, 2H), 3.36 (s, 2H), 2.72-2.62 (m, 4H).

B)6-Benzyl-N-((6-methoxypyridin-3-yl)methyl)-5,6,7,8-tetrahydropyrido[4,3-d]pyrimidin-4-amine

A mixture of6-benzyl-N-((6-chloropyridin-3-yl)methyl)-5,6,7,8-tetrahydropyrido[4,3-d]pyrimidin-4-amine(2.5 g, 6.8 mmol), MeOH (5 mL), and 15% wt. sodium methoxide solution(10 g, 48 mmol) in MeOH was subjected to microwave irradiation at 150°C. for 60 min. The mixture was concentrated in vacuo and the residue wastreated with water (50 mL) and extracted with CH₂Cl₂ (3×50 mL). Thecombined organic layers were washed with brine, dried (Na₂SO₄), andconcentrated. The residue was purified by silica gel column(MeOH/CH₂Cl₂: 0-15%) to yield a yellow solid (2.0 g, 79%).

LC-MS: 362.3 [M+H]⁺

¹H NMR (400 MHz, d6-DMSO): δ 0.24 (s, 1H), 8.09 (d, 1H, J=2.0 Hz), 7.62(dd, 1H, J=8.4, 2.4 Hz), 7.40-7.19 (m, 6H), 6.74 (d, 1H, J=8.4 Hz), 4.48(d, 2H, J=5.6 Hz), 3.80 (s, 3H), 3.70 (s, 2H), 3.32 (s, 2H), 2.70-2.60(m, 4H).

C)N-((6-Methoxypyridin-3-yl)methyl)-5,6,7,8-tetrahydropyrido[4,3-d]pyrimidin-4-amine

A mixture of6-benzyl-N-((6-methoxypyridin-3-yl)methyl)-5,6,7,8-tetrahydropyrido[4,3-d]pyrimidin-4-amine(1.90 g, 5.26 mmol), MeOH (100 mL), and 10% Pd—C (600 mg) washydrogenated at 1 atm for 3 days. LC-MS indicated complete conversion.Catalyst was filtered off and the filtrate was concentrated in vacuo toyield a light yellow foam.

LC-MS: 272.1 [M+H]⁺

D)5-Chloro-2-(4-((6-methoxypyridin-3-yl)methylamino)-7,8-dihydropyrido[4,3-d]pyrimidin-6(5H)-yl)benzonitrile

A mixture ofN-((6-methoxypyridin-3-yl)methyl)-5,6,7,8-tetrahydropyrido[4,3-d]pyrimidin-4-amine(440 mg, 1.6 mmol), 5-chloro-2-fluorobenzonitrile (630 mg, 4.0 mmol),N,N-diisopropylethylamine (560 uL, 3.2 mmol), and acetonitrile (4.0 mL)was subjected to microwave irradiation at 180° C. for 4 h. After that anadditional 5-chloro-2-fluorobenzonitrile (400 mg) was added and themixture was subjected to microwave irradiation at 180° C. for another 2h. After cooling, the mixture was treated with aq. NaHCO₃ and EtOAc (100mL). The organic layer was separated, washed with brine, dried (Na₂SO₄),and concentrated in vacuo. The residue was purified by silica gel column(EtOAc: 100%) and the obtained solid was washed with ether to yield anoff-white solid (290 mg, 44%).

LC-MS: 407.1 [M+H]⁺

¹H NMR (400 MHz, d6-DMSO): δ 8.32 (s, 1H), 8.15 (d, 1H, J=2.0 Hz), 7.93(d, 1H, J=2.8 Hz), 7.75 (dd, 1H, J=9.2, 2.8 Hz), 7.67 (dd, 1H, J=8.4,2.4 Hz), 7.44 (t, 1H, J=5.6 Hz), 7.31 (d, 1H, J=9.2 Hz), 6.76 (d, 1H,J=8.4 Hz), 4.57 (d, 2H, J=5.6 Hz), 4.02 (s, 2H), 3.81 (s, 3H), 3.57 (t,2H, J=5.6 Hz), 2.85 (t, 2H, J=5.6 Hz).

Method K Compound 145-Bromo-2-(4-((6-methoxypyridin-3-yl)methylamino)-7,8-dihydropyrido[4,3-d]pyrimidin-6(5H)-yl)benzonitrile

A mixture ofN-((6-methoxypyridin-3-yl)methyl)-5,6,7,8-tetrahydropyrido[4,3-d]pyrimidin-4-amine(350 mg, 1.3 mmol), 5-bromo-2-fluorobenzonitrile (640 mg, 3.2 mmol),N,N-diisopropylethylamine (0.67 mL, 3.9 mmol), and acetonitrile (4 mL)was subjected to microwave irradiation at 180° C. for 3 h. After thatadditional 5-bromo-2-fluorobenzonitrile (450 mg) was added and themixture was subjected to microwave irradiation at 180° C. for another 2h. After cooling, the mixture was diluted with EtOAc (100 mL) and washedwith aq. Na₂CO₃ solution and brine, dried (Na₂SO₄) and concentrated. Theresidue was purified by silica gel column (EtOAc: 100%) to yield a lightyellow solid.

LC-MS: 453.1 [M+H]⁺

¹H NMR (400 MHz, d6-DMSO): δ 8.32 (s, 1H), 8.14 (d, 1H, J=2.0 Hz), 8.02(d, 1H, J=2.4 Hz), 7.86 (dd, 1H, J=9.2, 2.4 Hz), 7.67 (dd, 1H, J=8.4,2.4 Hz), 7.44 (t, 1H, J=5.6 Hz), 7.24 (d, 1H, J=8.8 Hz), 6.76 (d, 1H,J=8.4 Hz), 4.57 (d, 2H, J=5.6 Hz), 4.01 (s, 2H), 3.81 (s, 3H), 3.57 (t,2H, J=5.6 Hz), 2.85 (t, 2H, J=5.6 Hz).

Method L Compound 152-(4-((6-Methoxypyridin-3-yl)methylamino)-7,8-dihydropyrido[4,3-d]pyrimidin-6(5H)-yl)-5-methylbenzonitrile

To a mixture of5-bromo-2-(4-((6-methoxypyridin-3-yl)methylamino)-7,8-dihydropyrido[4,3-d]pyrimidin-6(5H)-yl)benzonitrile(55 mg, 0.12 mmol), methylboronic acid (18 mg, 0.30 mmol), potassiumphosphate (90.6 mg, 0.427 mmol), tricyclohexylphosphine (6.8 mg, 0.024mmol), toluene (3 mL), and water (0.2 mL) under argon was addedpalladium acetate (2.7 mg, 0.012 mmol). The mixture was heated at 100°C. for 3 h and then cooled to rt. The mixture was filtered throughCelite and the filter cake was washed with EtOAc. The filtrate wasconcentrated and the residue was purified by preparative HPLC to yieldan off-white solid.

LC-MS: 387.1 [M+H]⁺

¹H NMR (400 MHz, d6-DMSO): δ 8.31 (s, 1H), 8.14 (d, 1H, J=2.0 Hz), 7.67(dd, 1H, J=8.8, 2.4 Hz), 7.58 (d, 1H, J=1.2 Hz), 7.49 (dd, 1H, J=8.4,1.6 Hz), 7.42 (t, 1H, J=5.6 Hz), 7.23 (d, 1H, J=8.8 Hz), 6.76 (d, 1H,J=8.8 Hz), 4.57 (d, 2H, J=5.6 Hz), 3.97 (s, 2H), 3.81 (s, 3H), 3.48 (t,2H, J=5.6 Hz), 2.83 (t, 2H, J=5.6 Hz), 2.28 (s, 3H).

Method M Compound 205-Chloro-2-{4-[(R)-3-hydroxy-1-(6-trifluoromethyl-pyridin-3-yl)-propylamino]-7,8-dihydro-5H-pyrido[4,3-d]pyrimidin-6-yl}-benzonitrile

A reaction mixture of2-(4-bromo-7,8-dihydropyrido[4,3-d]pyrimidin-6(5H)-yl)-5-chlorobenzonitrile(35 mg, 0.10 mmol) and(R)-3-amino-3-(6-(trifluoromethyl)pyridin-3-yl)propan-1-ol (22 mg, 0.10mmol) in acetonitrile (1 mL) and N,N-diisopropylethylamine (0.035 mL,0.20 mmol) was subjected to microwave irradiation at 200° C. for 2 h.The reaction mixture was concentrated and the residue was purified bypreparative HPLC (100×20.2 mm, C18 column; 30-70% CH₃CN-water [10 mMEt₂NH]) to yield an off-white solid.

LC-MS: 489.2 [M+H]⁺

¹H NMR (400 MHz, d6-DMSO): δ 8.80 (s, 1H), 8.24 (s, 1H), 8.05 (d, 1H,J=8.4 Hz), 7.96 (d, 1H, J=2.8 Hz), 7.85 (d, 1H, J=8.4 Hz), 7.79 (dd, 1H,J=8.8, 2.4 Hz), 7.39 (d, 1H, J=8.8 Hz), 7.23 (d, 1H, J=7.6 Hz), 5.52 (m,1H), 4.68 (t, 1H, J=4.8 Hz), 4.18 and 4.07 (AB, 2H, J=15.6 Hz),3.60-3.40 (m, 4H), 2.85 (m, 2H), 2.12 (m, 1H), 1.97 (m, 1H).

Method N Compound 212-{4-[(R)-3-Hydroxy-1-(6-methyl-pyridin-3-yl)-propylamino]-7,8-dihydro-5H-pyrido[4,3-d]pyrimidin-6-yl}-5-methyl-benzonitrile

A reaction mixture of2-(4-chloro-7,8-dihydropyrido[4,3-d]pyrimidin-6(5H)-yl)-5-methylbenzonitrile(60 mg, 0.21 mmol) and (R)-3-amino-3-(6-methylpyridin-3-yl)propan-1-ol(35 mg, 0.21 mmol) in acetonitrile (2 mL) and N,N-diisopropylethylamine(73 μL, 0.42 mmol) was subjected to microwave irradiation at 180° C. for3 h. The reaction mixture was concentrated and the residue was purifiedby silica gel column (0-30% MeOH/CH₂Cl₂) followed by preparative HPLC(100×20.2 mm, C18 column; 20-50% CH₃CN-water [10 mM Et₂NH]) to yield anoff-white solid (29 mg).

LC-MS: 415.5 [M+H]⁺

¹H NMR (400 MHz, d6-DMSO): δ 8.45 (d, 1H, J=1.6 Hz), 8.23 (s, 1H), 7.65(dd, 1H, J=8.0, 2.4 Hz), 7.60 (d, 1H, J=1.6 Hz), 7.52 (dd, 1H, J=8.4,1.6 Hz), 7.31 (d, 1H, J=8.4 Hz), 7.16 (d, 1H, J=8.0 Hz), 7.07 (d, 1H,J=8.0 Hz), 5.40 (m, 1H), 4.61 (t, 1H, J=4.8 Hz), 4.07 and 3.99 (AB, 2H,J=15.6 Hz), 3.53-3.38 (m, 4H), 2.82 (m, 2H), 2.40 (s, 3H), 2.30 (s, 3H),2.08 (m, 1H), 1.91 (m, 1H).

Method O Compound 302-{4-[(5-Cyclopropyl-pyridin-2-ylmethyl)-amino]-7,8-dihydro-5H-pyrido[4,3-d]pyrimidin-6-yl}-5-methyl-benzonitrile

A reaction mixture of2-(4-chloro-7,8-dihydropyrido[4,3-d]pyrimidin-6(5H)-yl)-5-methylbenzonitrile(150 mg, 0.53 mmol) and (5-cyclopropylpyridin-2-yl)methanamine (115 mg,0.78 mmol) in acetonitrile (2 mL) and N,N-diisopropylethylamine (0.14mL, 0.78 mmol) was subjected to microwave irradiation at 180° C. for 2h. The mixture was concentrated and the residue was purified bypreparative HPLC (100×20.2 mm, C18 column; 50-70% CH₃CN-water [10 mMEt₂NH]) to yield an off-white foam.

LC-MS: 397.3 [M+H]⁺

¹H NMR (400 MHz, d6-DMSO): δ 8.32 (d, 1H, J=2.0 Hz), 8.25 (s, 1H), 7.59(d, 1H, J=1.2 Hz), 7.55-7.47 (m, 2H), 7.32 (dd, 1H, J=8.4, 2.0 Hz), 7.25(d, 1H, J=8.4 Hz), 7.16 (d, 1H, J=8.0 Hz), 4.67 (d, 2H, J=5.6 Hz), 4.03(s, 2H), 3.51 (t, 2H, J=5.6 Hz), 2.85 (t, 2H, J=5.6 Hz), 2.29 (s, 3H),191 (m, 1H), 0.99-0.93 (m, 2H), 0.70-0.65 (m, 2H).

Method P Compound 355-Chloro-2-{4-[(S)-2-hydroxy-1-(6-methoxy-pyridin-3-yl)-ethylamino]-7,8-dihydro-5H-pyrido[4,3-d]pyrimidin-6-yl}-benzonitrile

A reaction mixture of5-chloro-2-(4-chloro-7,8-dihydropyrido[4,3-d]pyrimidin-6(5H)-yl)benzonitrile(250 mg, 0.82 mmol) and (S)-2-amino-2-(6-methoxypyridin-3-yl)ethanol(110 mg, 0.68 mmol) in acetonitrile (3 mL) and N,N-diisopropylethylamine(240 μL, 1.4 mmol) was subjected to microwave irradiation at 180° C. for4 h. The reaction mixture was concentrated and the residue was purifiedby silica gel column (0-15% MeOH/CH₂Cl₂) to yield a crude product whichwas recrystallized from MeOH to yield colorless crystals.

LC-MS: 437.4 [M+H]⁺

¹H NMR (400 MHz, d6-DMSO): δ 8.27 (s, 1H), 8.18 (d, 1H, J=2.4 Hz), 7.95(d, 1H, J=2.4 Hz), 7.78 (dd, 1H, J=8.8, 2.4 Hz), 7.72 (dd, 1H, J=8.4,2.4 Hz), 7.41 (d, 1H, J=8.8 Hz), 6.97 (d, 1H, J=8.0 Hz), 6.76 (d, 1H,J=8.4 Hz), 5.32 (m, 1H), 4.99 (t, 1H, J=6.0 Hz), 4.13 and 4.06 (AB, 2H,J=15.6 Hz), 3.81 (s, 3H), 3.80-3.63 (m, 2H), 3.56 (t, 2H, J=5.6 Hz),2.84 (m, 2H).

Method Q Compound 372-{4-[(Imidazo[1,2-a]pyridin-7-ylmethyl)-amino]-7,8-dihydro-5H-pyrido[4,3-d]pyrimidin-6-yl}-5-methyl-benzonitrile

A reaction mixture of2-(4-chloro-7,8-dihydropyrido[4,3-d]pyrimidin-6(5H)-yl)-5-methylbenzonitrile(300 mg, 1.05 mmol) and imidazo[1,2-a]pyridin-7-ylmethanamine (400 mg,2.31 mmol) in acetonitrile (10 mL) and N,N-diisopropylethylamine (1.0mL, 5.7 mmol) was subjected to microwave irradiation at 185° C. for 2.5h. The reaction mixture was concentrated and purified bysemi-preparative HPLC (100×20.2 mm, C18 column; 30-60% CH₃CN-water [10mM Et₂NH]) to yield a light yellow solid.

LC-MS: 396.4 [M+H]⁺

¹H NMR (400 MHz, d6-DMSO): δ 8.46 (d, 1H, J=6.9 Hz), 8.30 (s, 1H), 7.87(s, 1H), 7.59 (d, 1H, J=1.4 Hz), 7.54 (t, 1H, J=5.8 Hz), 7.50 (s, 1H),7.48 (d, 1H, J=1.7 Hz), 7.38 (s, 1H), 7.25 (d, 1H, J=8.5 Hz), 6.86 (dd,1H, J=7.0, 1.5 Hz), 4.67 (d, 2H, J=5.7 Hz), 4.05 (s, 2H), 3.52 (t, 2H,J=5.5 Hz), 2.86 (t, 2H, J=5.3 Hz), 2.29 (s, 3H).

Method R Compound 382-{4-[(Benzooxazol-5-ylmethyl)-amino]-7,8-dihydro-5H-pyrido[4,3-d]pyrimidin-6-yl}-5-methyl-benzonitrile

A reaction mixture of2-(4-chloro-7,8-dihydropyrido[4,3-d]pyrimidin-6(5H)-yl)-5-methylbenzonitrile(100 mg, 0.35 mmol) and benzo[d]oxazol-5-ylmethanamine (150 mg, 0.41mmol) in acetonitrile (3 mL) and N,N-diisopropylethylamine (0.37 mL, 2.1mmol) was subjected to microwave irradiation at 185° C. for 2.5 h. Thereaction mixture was concentrated and purified by preparative HPLC(100×20.2 mm, C18 column; 30-60% CH₃CN-water [10 mM Et₂NH]) to yield alight yellow solid.

LC-MS: 397.4 [M+H]⁺

¹H NMR (400 MHz, d6-DMSO): δ 8.71 (s, 1H), 8.30 (s, 1H), 7.75 (d, 1H,J=0.9 Hz), 7.70 (d, 1H, J=8.4 Hz), 7.58 (d, 1H, J=1.5 Hz), 7.55 (t, 1H,J=5.9 Hz), 7.49 (dd, 1H, J=8.5, 1.7 Hz), 7.42 (dd, 1H, J=8.4, 1.5 Hz),7.25 (d, 1H, J=8.5 Hz), 4.77 (d, 2H, J=5.8 Hz), 4.02 (s, 2H), 3.51 (t,2H, J=5.6 Hz), 2.85 (t, 2H, J=5.4 Hz), 2.29 (s, 3H).

Method S Compound 395-Methyl-2-{4-[(2-methyl-pyrimidin-5-ylmethyl)-amino]-7,8-dihydro-5H-pyrido[4,3-d]pyrimidin-6-yl}-benzonitrile

A reaction mixture of2-(4-chloro-7,8-dihydropyrido[4,3-d]pyrimidin-6(5H)-yl)-5-methylbenzonitrile(400 mg, 1.41 mmol) and (2-methylpyrimidin-5-yl)methanamine (400 mg,3.25 mmol) in acetonitrile (3 mL) and N,N-diisopropylethylamine (1.5 mL,8.6 mmol) was subjected to microwave irradiation at 185° C. for 2.5 h.The reaction mixture was concentrated and purified by preparative HPLC(100×20.2 mm, C18 column; 40-60% CH₃CN-water [10 mM Et₂NH]) to yield alight brown solid.

LC-MS: 372.2 [M+H]+

¹H NMR (400 MHz, d6-DMSO): δ 8.66 (s, 2H), 8.32 (s, 1H), 7.59 (d, 1H,J=1.5 Hz), 7.50 (d, 1H, J=2.4 Hz), 7.48 (d, 1H, J=1.3 Hz), 7.23 (d, 1H,J=8.5 Hz), 4.60 (d, 2H, J=5.6 Hz), 4.00 (s, 2H), 3.49 (t, 2H, J=5.6 Hz),2.85 (t, 2H, J=5.4 Hz), 2.57 (s, 3H), 2.29 (s, 3H).

Method T Compound 445-Chloro-2-{4-[(imidazo[1,2-a]pyridin-7-ylmethyl)-amino]-7,8-dihydro-5H-pyrido[4,3-d]pyrimidin-6-yl}-benzonitrile

A reaction mixture of5-chloro-2-(4-chloro-7,8-dihydropyrido[4,3-d]pyrimidin-6(5H)-yl)benzonitrile(250 mg, 0.82 mmol) and imidazo[1,2-a]pyridin-7-ylmethanamine (270 mg,1.83 mmol) in acetonitrile (10 mL) and N,N-diisopropylethylamine (1.0mL, 5.7 mmol) was subjected to microwave irradiation at 185° C. for 4 h.The reaction mixture was concentrated and purified by semi-preparativeHPLC (100×20.2 mm, C18 column; 40-60% CH₃CN-water [10 mM Et₂NH]) toyield a light yellow solid.

LC-MS: 416.4 [M+H]⁺

¹H NMR (400 MHz, d6-DMSO): δ 8.47 (d, 1H, J=7.0 Hz), 8.30 (s, 1H), 7.94(d, 1H, J=2.6 Hz), 7.87 (s, 1H), 7.76 (dd, 1H J=8.9, 2.6 Hz), 7.56 (t,1H, J=6.0 Hz), 7.50 (s, 1H), 7.36 (s, 1H), 7.33 (d, 1H, J=9.0 Hz), 6.87(dd, 1H, J=7.0, 1.4 Hz), 4.68 (d, 2H, J=5.7 Hz), 4.10 (s, 2H), 3.60 (t,2H, J=5.5 Hz), 2.88 (t, 2H, J=5.4 Hz).

Method U Compound 462-{4-[(S)-2-Hydroxy-1-(6-trifluoromethyl-pyridin-3-yl)-ethylamino]-7,8-dihydro-5H-pyrido[4,3-d]pyrimidin-6-yl}-5-methyl-benzonitrile

A reaction mixture of2-(4-chloro-7,8-dihydropyrido[4,3-d]pyrimidin-6(5H)-yl)-5-methylbenzonitrile(160 mg, 0.56 mmol) and(S)-2-amino-2-(6-(trifluoromethyl)pyridin-3-yl)ethanol (118 mg, 0.57mmol) (prepared similarly according to the method for Intermediate 10)in acetonitrile (2 mL) and N,N-diisopropylethylamine (0.4 mL) wassubjected to microwave irradiation at 185° C. for 3.5 h. The reactionmixture was concentrated and the residue was purified bysemi-preparative HPLC (100×20.2 mm, C18 column; 40-60%acetonitrile-water [10 mM diethylamine]) to yield a light brown solid.

LC-MS: 455.2 [M+H]⁺

¹H NMR (400 MHz, d6-DMSO): δ 8.81(d, 1H, J=1.5 Hz), 8.25 (s, 1H), 8.07(dd, 1H J=8.1, 1.7 Hz), 7.85 (d, 1H, J=8.1 Hz), 7.61 (d, 1H, J=1.5 Hz),7.53 (dd, 1H, J=8.6, 1.8 Hz), 7.33 (d, 1H, J=8.5 Hz), 7.11 (d, 1H, J=7.5Hz), 5.43 (q, 1H, J=6.8 Hz), 5.14 (t, 1H, J=5.9 Hz), 4.15 and 4.06 (AB,2H, J=15.5 Hz), 3.88-3.70 (m, 2H), 3.49 (t, 2H, J=5.7 Hz), 2.85 (m, 2H),2.30 (s, 3H).

Method V Compound 475-Chloro-2-{4-[(S)-2-hydroxy-1-(6-trifluoromethyl-pyridin-3-yl)-ethylamino]-7,8-dihydro-5H-pyrido[4,3-d]pyrimidin-6-yl}-benzonitrile

A reaction mixture of5-chloro-2-(4-chloro-7,8-dihydropyrido[4,3-d]pyrimidin-6(5H)-yl)benzonitrile(150 mg, 0.49 mmol) and(S)-2-amino-2-(6-(trifluoromethyl)pyridin-3-yl)ethanol (150 mg, 0.74mmol) (prepared similarly according to the method for Intermediate 10)in acetonitrile (3 mL) and N,N-diisopropylethylamine (170 μL, 0.98 mmol)was subjected to microwave irradiation at 180° C. for 4 h. The reactionmixture was concentrated and the residue was purified by silica gelcolumn (100% EtOAc and then 0-20% MeOH/CH₂Cl₂) followed bysemi-preparative HPLC (100×20.2 mm, C18 column; 30-70%acetonitrile-water [10 mM Et₂NH]) to yield a light yellow foam (44 mg).

LC-MS: 475.4 [M+H]⁺

¹H NMR (400 MHz, d6-DMSO): δ 8.81 (d, 1H, J=1.6 Hz), 8.26 (s, 1H), 8.08(dd, 1H, J=8.0, 1.6 Hz), 7.96 (d, 1H, J=2.8 Hz), 7.85 (d, 1H, J=7.6 Hz),7.79 (dd, 1H, J=9.2, 2.8 Hz), 7.41 (d, 1H, J=9.2 Hz), 7.13 (d, 1H, J=7.6Hz), 5.44 (q, 1H, J=6.8 Hz), 5.15 (t, 1H, J=5.6 Hz), 4.20 and 4.10 (AB,2H, J=15.6 Hz), 3.87-3.74 (m, 2H), 3.57 (t, 2H, J=5.6 Hz), 2.86 (t, 2H,J=5.6 Hz).

Method W Compound 515-Chloro-2-[4-(3-[1,2,4]triazol-4-yl-benzylamino)-7,8-dihydro-5H-pyrido[4,3-d]pyrimidin-6-yl]-benzonitrile

A reaction mixture of5-chloro-2-(4-chloro-7,8-dihydropyrido[4,3-d]pyrimidin-6(5H)-yl)benzonitrile(80 mg, 0.26 mmol) and (3-(4H-1,2,4-triazol-4-yl)phenyl)methanamine (120mg, 0.40 mmol) in acetonitrile (1 mL) and N,N-diisopropylethylamine (0.6mL, 4 mmol) was subjected to microwave irradiation at 185° C. for 2.5 h.The reaction mixture was concentrated and purified by semi-preparativeHPLC (100×20.2 mm, C18 column; 30-50% CH₃CN-water [10 mM Et₂NH]) toyield a light yellow solid.

LC-MS: 443.5 [M+H]⁺

¹H NMR (400 MHz, d6-DMSO): δ 9.10 (s, 2H), 8.30 (s, 1H), 7.94 (d, 1H,J=2.6 Hz), 7.76 (dd, 1H, J=8.9, 2.6 Hz), 7.66 (s, 1H), 7.60-7.52 (m,2H), 7.50 (t, 1H, J=7.8 Hz), 7.38 (d, 1H, J=7.6 Hz), 7.33 (d, 1H, J=9.0Hz), 4.73 (d, 2H, J=5.7 Hz), 4.09 (s, 2H), 3.59 (t, 2H, J=5.5 Hz), 2.87(t, 2H, J=5.4 Hz).

Method X Compound 575-Chloro-2-{4-[(R)-1-(2-methoxy-pyrimidin-5-yl)-ethylamino]-7,8-dihydro-5H-pyrido[4,3-d]pyrimidin-6-yl}-benzonitrile

A reaction mixture of5-chloro-2-(4-chloro-7,8-dihydropyrido[4,3-d]pyrimidin-6(5H)-yl)benzonitrile(130 mg, 0.41 mmol) and (R)-1-(2-methoxypyrimidin-5-yl)ethanamine (85mg, 0.55 mmol) (prepared similarly according to the method forIntermediate 16) in acetonitrile (3 mL) and N,N-diisopropylethylamine(140 μL, 0.83 mmol) was subjected to microwave irradiation at 180° C.for 3 h. The reaction mixture was concentrated and the residue waspurified by semi-preparative HPLC (100×20.2 mm, C18 column; 30-60%acetonitrile-water [10 mM Et₂NH]) to yield a white solid.

LC-MS: 422.4 [M+H]⁺

¹H NMR (400 MHz, d6-DMSO): δ 8.62 (s, 2H), 8.29 (s, 1H), 7.94 (d, 1H,J=2.8 Hz), 7.77 (dd, 1H, J=8.8, 2.8 Hz), 7.37 (d, 1H, J=8.8 Hz), 7.10(d, 1H, J=7.2 Hz), 5.39 (p, 1H, J=7.2 Hz), 4.12 and 4.02 (AB, 2H, J=15.6Hz), 3.88 (s, 3H), 3.56 (m, 2H), 2.85 (t, 2H, J=5.6 Hz), 1.55 (d, 3H,J=7.2 Hz).

Method Y Compound 582-{4-[(R)-1-(2-Methoxy-pyrimidin-5-yl)-ethylamino]-7,8-dihydro-5H-pyrido[4,3-d]pyrimidin-6-yl}-5-methyl-benzonitrile

A reaction mixture of2-(4-chloro-7,8-dihydropyrido[4,3-d]pyrimidin-6(5H)-yl)-5-methylbenzonitrile(430 mg, 1.51 mmol) and (R)-1-(2-methoxypyrimidin-5-yl)ethanamine (238mg, 1.56 mmol) (prepared similarly according to the method forIntermediate 16) in acetonitrile (6 mL) and N,N-diisopropylethylamine (2mL, 9 mmol) was subjected to microwave irradiation at 185° C. for 3.5 h.The reaction mixture was concentrated and the residue was purified bysemi-preparative HPLC (100×20.2 mm, C18 column; 30-60%acetonitrile-water [10 mM Et₂NH]) to yield a light yellow solid.

LC-MS: 402.0 [M+1-1]⁺

¹H NMR (400 MHz, d6-DMSO): δ 8.62 (s, 2H), 8.29 (s, 1H), 7.59 (d, 1H,J=1.5 Hz), 7.51 (dd, 1H, J=8.5, 1.6 Hz), 7.29 (d, 1H, J=8.5 Hz), 7.09(d, 1H, J=7.5 Hz), 5.39 (p, 1H, J=7.2 Hz), 4.07 and 3.98 (AB, 2H, J=15.5Hz), 3.88 (s, 3H), 3.55-3.40 (m, 2H), 2.84 (t, 2H, J=5.4 Hz), 2.29 (s,3H), 1.55 (d, 3H, J=7.1 Hz).

Method Z Compound 602-{4-[(S)-2-Hydroxy-1-(2-methoxy-pyrimidin-5-yl)-ethylamino]-7,8-dihydro-5H-pyrido[4,3-d]pyrimidin-6-yl}-5-methyl-benzonitrile

A)(S)-2-(4-(2-(tert-butyldimethylsilyloxy)-1-(2-methoxypyrimidin-5-yl)ethylamino)-7,8-dihydropyrido[4,3-d]pyrimidin-6(5H)-yl)-5-methylbenzonitrile

A reaction mixture of2-(4-chloro-7,8-dihydropyrido[4,3-d]pyrimidin-6(5H)-yl)-5-methylbenzonitrile(500 mg, 1.76 mmol) and(S)-2-(tert-butyldimethylsilyloxy)-1-(2-methoxypyrimidin-5-yl)ethanamine(800 mg, 2.82 mmol) in acetonitrile (10 mL) andN,N-diisopropylethylamine (1 mL) was subjected to microwave irradiationat 185° C. for 3 h. The reaction mixture was concentrated and theresidue was purified by silica-gel column to afford a light yellowsolid.

LC-MS: 532.5 [M+H]⁺

B)2-{4-[(S)-2-hydroxy-1-(2-methoxy-pyrimidin-5-yl)-ethylamino]-7,8-dihydro-5H-pyrido[4,3-d]pyrimidin-6-yl}-5-methyl-benzonitrile

To a solution of(S)-2-(4-(2-(tert-butyldimethylsilyloxy)-1-(methoxypyrimidin-5-yl)ethylamino)-7,8-dihydropyrido[4,3-d]pyrimidin-6(5H)-yl)-5-methylbenzonitrile(740 mg, 1.39 mmol) in THF (10 mL) was added 1M TBAF in THF (5 mL). Thereaction mixture was stirred at room temperature for 10 minutes, andthen treated with water and EtOAc. The organic layer was washed with aq.NaHCO₃ and brine, dried (MgSO₄), and concentrated. The residue waspurified by semi-preparative HPLC to yield a white solid.

LC-MS: 418.4 [M+H]⁺

¹H NMR (400 MHz, d6-DMSO): δ 8.62 (s, 2H), 8.28 (s, 1H), 7.60 (d, 1H,J=1.5 Hz), 7.51 (dd, 1H, J=8.5, 1.7 Hz), 7.31 (d, 1H, J=8.5 Hz), 6.97(d, 1H, J=7.7 Hz), 5.31 (q, 1H, J=6.7 Hz), 5.08 (t, 1H, J=5.9 Hz), 4.11and 4.01 (AB, 2H, J=15.5 Hz), 3.88 (s, 3H), 3.85-3.67 (m, 2H), 3.48 (t,2H, J=5.7 Hz), 2.91-2.78 (m, 2H), 2.30 (s, 3H).

Method AA Compound 612-{4-[(2-Isopropyl-pyrimidin-5-ylmethyl)-amino]-7,8-dihydro-5H-pyrido[4,3-d]pyrimidin-6-yl}-5-methyl-benzonitrile

A reaction mixture of2-(4-chloro-7,8-dihydropyrido[4,3-d]pyrimidin-6(5H)-yl)-5-methylbenzonitrile(80 mg, 0.28 mmol) and (2-isopropylpyrimidin-5-yl)methanamine (60 mg,0.40 mmol) (prepared similarly according to the method for Intermediate13) in acetonitrile (1 mL) and N,N-diisopropylethylamine (0.3 mL, 2mmol) was subjected to microwave irradiation at 185° C. for 3 h. Thereaction mixture was concentrated and purified by semi-preparative HPLC(100×20.2 mm, C18 column; 40-60% CH₃CN-water [10 mM Et₂NH]) to yield alight yellow solid.

LC-MS: 400.4 [M+H]⁺

¹H NMR (400 MHz, d6-DMSO): δ 8.70 (s, 2H), 8.33 (s, 1H), 7.59 (d, 1H,J=1.5 Hz), 7.53-7.45 (m, 2H), 7.23 (d, 1H, J=8.5 Hz), 4.60 (d, 2H, J=5.6Hz), 4.00 (s, 2H), 3.49 (t, 2H, J=5.6 Hz), 3.18-3.03 (m, 1H), 2.84 (t,2H, J=5.5 Hz), 2.29 (s, 3H), 1.24 (d, 6H, J=6.8 Hz).

Method AB Compound 642-{4-[(R)-3-Hydroxy-1-(6-trifluoromethyl-pyridin-3-yl)-propylamino]-7,8-dihydro-5H-pyrido[4,3-d]pyrimidin-6-yl}-5-methyl-benzonitrile

A reaction mixture of2-(4-chloro-7,8-dihydropyrido[4,3-d]pyrimidin-6(5H)-yl)-5-methylbenzonitrile(200 mg, 0.70 mmol) and(R)-3-amino-3-(6-(trifluoromethyl)pyridin-3-yl)propan-1-ol (180 mg, 0.82mmol) in acetonitrile (2 mL) and N,N-diisopropylethylamine (0.7 mL, 4mmol) was subjected to microwave irradiation at 185° C. for 2.5 h. Thereaction mixture was concentrated and the residue was purified bysemi-preparative HPLC (100×20.2 mm, C18 column; 40-60%acetonitrile-water [10 mM Et₂NH]) to yield an off-white solid.

LC-MS: 469.4 [M+H]⁺

¹H NMR (400 MHz, d6-DMSO): δ 8.80 (d, 1H, J=0.9 Hz), 8.23 (s, 1H), 8.05(dd, 1H, J=8.1, 1.4 Hz), 7.85 (d, 1H, J=8.1 Hz), 7.61 (d, 1H, J=1.4 Hz),7.53 (dd, 1H, J=8.5, 1.6 Hz), 7.31 (d, 1H, J=8.4 Hz), 7.22 (d, 1H, J=7.5Hz), 5.52 (q, 1H, J=5.7 Hz), 4.69 (t, 1H, J=4.7 Hz), 4.13 and 4.03 (AB,2H, J=15.5 Hz), 3.60-3.40 (m, 4H), 2.83 (m, 2H), 2.31 (s, 3H), 2.23-2.08(m, 1H), 2.03-1.90 (m, 1H).

Method AC Compound 665-Methyl-2-{4-[(R)-1-(2-methyl-pyrimidin-5-yl)-ethylamino]-7,8-dihydro-5H-pyrido[4,3-d]pyrimidin-6-yl}-benzonitrile

A reaction mixture of2-(4-chloro-7,8-dihydropyrido[4,3-d]pyrimidin-6(5H)-yl)-5-methylbenzonitrile(350 mg, 1.23 mmol) and (R)-1-(2-methylpyrimidin-5-yl)ethanamine (300mg, 2.19 mmol) in acetonitrile (3 mL) and N,N-diisopropylethylamine(0.86 mL, 4.9 mmol) was subjected to microwave irradiation at 185° C.for 3.5 h. The reaction mixture was concentrated and the residue waspurified by semi-preparative HPLC (100×20.2 mm, C18 column; 30-55%acetonitrile-water [10 mM Et₂NH]) to yield an off-white solid.

LC-MS: 386.1 [M+H]⁺

¹H NMR (400 MHz, d6-DMSO): δ 8.70 (s, 2H), 8.27 (s, 1H), 7.59 (d, 1H,J=1.5 Hz), 7.51 (dd, 1H, J=8.5, 1.7 Hz), 7.30 (d, 1H, J=8.4 Hz), 7.13(d, 1H, J=7.4 Hz), 5.39 (m, 1H), 4.09 and 3.99 (AB, 2H, J=15.5 Hz),3.55-3.20 (m, 2H), 2.84 (t, 2H, J=5.3 Hz), 2.57 (s, 3H), 2.30 (s, 3H),1.56 (d, 3H, J=7.1 Hz).

Method AD Compound 675-Methyl-2-{4-[(S)-1-(2-methyl-pyrimidin-5-yl)-ethylamino]-7,8-dihydro-5H-pyrido[4,3-d]pyrimidin-6-yl}-benzonitrile

A reaction mixture of2-(4-chloro-7,8-dihydropyrido[4,3-d]pyrimidin-6(5H)-yl)-5-methylbenzonitrile(60 mg, 0.21 mmol) and (S)-1-(2-methylpyrimidin-5-yl)ethanamine (29 mg,0.21 mmol) in acetonitrile (2 mL) and N,N-diisopropylethylamine (74 μL,0.42 mmol) was subjected to microwave irradiation at 180° C. for 1 h.The reaction mixture was concentrated and the residue was purified bysemi-preparative HPLC (100×20.2 mm, C18 column; 30-60%acetonitrile-water [10 mM Et₂NH]) to yield an off-white solid.

LC-MS: 385.9 [M+H]⁺

¹H NMR (400 MHz, d6-DMSO): δ 8.70 (s, 2H), 8.26 (s, 1H), 7.59 (d, 1H,J=1.6 Hz), 7.51 (dd, 1H, J=8.4, 1.6 Hz), 7.29 (d, 1H, J=8.4 Hz), 7.13(d, 1H, J=7.2 Hz), 5.39 (p, 1H, J=7.2 Hz), 4.09 and 3.99 (AB, 2H, J=15.6Hz), 3.48 (m, 2H), 2.84 (t, 2H, J=5.2 Hz), 2.57 (s, 3H), 2.30 (s, 3H),1.55 (d, 3H, J=7.2 Hz).

Method AE Compound 735-Chloro-2-{4-[(S)-2-hydroxy-1-(2-methyl-pyrimidin-5-yl)-ethylamino]-7,8-dihydro-5H-pyrido[4,3-d]pyrimidin-6-yl}-benzonitrile

A)(S)-2-(4-(2-(tert-Butyldimethylsilyloxy)-1-(2-methylpyrimidin-5-yl)ethylamino)-7,8-dihydropyrido[4,3-d]pyrimidin-6(5H)-yl)-5-chlorobenzonitrile

A reaction mixture of5-chloro-2-(4-chloro-7,8-dihydropyrido[4,3-d]pyrimidin-6(5H)-yl)benzonitrile(150 mg, 0.49 mmol) and(S)-2-(tert-butyldimethylsilyloxy)-1-(2-methylpyrimidin-5-yl)ethanamine(144 mg, 0.54 mmol) in acetonitrile (2 mL) and N,N-diisopropylethylamine(0.5 mL, 3 mmol) was subjected to microwave irradiation at 185° C. for3.5 h. The reaction mixture was concentrated and the residue waspurified by semi-preparative HPLC to yield the product as a yellowsolid.

LC-MS: 536.7 [M+H]⁺

B)5-Chloro-2-{4-[(S)-2-hydroxy-1-(2-methyl-pyrimidin-5-yl)-ethylamino]-7,8-dihydro-5H-pyrido[4,3-d]pyrimidin-6-yl}-benzonitrile

To a solution of(S)-2-(4-(2-(tert-butyldimethylsilyloxy)-1-(2-methylpyrimidin-5-yl)ethylamino)-7,8-dihydropyrido[4,3-d]pyrimidin-6(5H)-yl)-5-chlorobenzonitrile(60 mg, 0.11 mmol) in THF (10 mL) was added 1M TBAF in THF (5 mL). Thereaction mixture was stirred at room temperature for 10 minutes, andthen treated with water and EtOAc. The organic layer was washed with aq.NaHCO₃ and brine, dried (MgSO₄), and concentrated. The residue waswashed by ethyl ether and water (to completely remove TBAF) and dried toyield the final product as a light colored solid.

LC-MS: 422.5 [M+H]⁺

¹H NMR (400 MHz, d6-DMSO): δ 8.70 (s, 2H), 8.27 (s, 1H), 7.94 (d, 1H,J=2.6 Hz), 7.77 (dd, 1H, J=8.9, 2.6 Hz), 7.41 (d, 1H, J=9.0 Hz), 7.04(d, 1H, J=8.0 Hz), 5.32 (q, 1H, J=6.8 Hz), 5.12 (t, 1H, J=5.9 Hz), 4.18and 4.08 (AB, 2H, J=15.5 Hz), 3.88-3.68 (m, 2H), 3.57 (t, 2H, J=5.6 Hz),2.86 (t, 2H, J=5.6 Hz), 2.57 (s, 3H).

Method AF Compound 742-{4-[(S)-2-Hydroxy-1-(2-methyl-pyrimidin-5-yl)-ethylamino]-7,8-dihydro-5H-pyrido[4,3-d]pyrimidin-6-yl}-5-methyl-benzonitrile

A)(S)-2-(4-(2-(tert-Butyldimethylsilyloxy)-1-(2-methylpyrimidin-5-yl)ethylamino)-7,8-dihydropyrido[4,3-d]pyrimidin-6(5H)-yl)-5-methylbenzonitrile

A reaction mixture of2-(4-chloro-7,8-dihydropyrido[4,3-d]pyrimidin-6(5H)-yl)-5-methylbenzonitrile(420 mg, 1.48 mmol) and(S)-2-(tert-butyldimethylsilyloxy)-1-(2-methylpyrimidin-5-yl)ethanamine(742 mg, 2.78 mmol) in acetonitrile (8 mL) and N,N-diisopropylethylamine(1 mL) was subjected to microwave irradiation at 185° C. for 3 h. Thereaction mixture was concentrated and the residue was purified bysilica-gel column to yield the product as a light yellow solid.

LC-MS: 516.5 [M+H]⁺

B)2-{4-[(S)-2-Hydroxy-1-(2-methyl-pyrimidin-5-yl)-ethylamino]-7,8-dihydro-5H-pyrido[4,3-d]pyrimidin-6-yl}-5-methyl-benzonitrile

To a solution of(S)-2-(4-(2-(tert-butyldimethylsilyloxy)-1-(2-methylpyrimidin-5-yl)ethylamino)-7,8-dihydropyrido[4,3-d]pyrimidin-6(5H)-yl)-5-methylbenzonitrile(630 mg, 1.22 mmol) in THF (10 mL) was added 1M TBAF in THF (5 mL). Thereaction mixture was stirred at room temperature for 10 minutes, andthen treated with water and EtOAc. The organic layer was washed with aq.NaHCO₃ and brine, dried (MgSO₄), and concentrated. The residue waswashed by ethyl ether to yield a light colored solid.

LC-MS: 402.3 [M+H]⁺

¹H NMR (400 MHz, d6-DMSO): δ 8.70 (s, 2H), 8.27 (s, 1H), 7.60 (d, 1H,J=1.4 Hz), 7.51 (dd, 1H, J=8.5, 1.7 Hz), 7.32 (d, 1H, J=8.4 Hz), 7.02(d, 1H, J=7.6 Hz), 5.32 (q, 1H, J=6.8 Hz), 5.11 (t, 1H, J=5.9 Hz), 4.13and 4.02 (AB, 2H, J=15.5 Hz), 3.88-3.68 (m, 2H), 3.48 (t, 2H, J=5.6 Hz),2.92-2.75 (m, 2H), 2.57 (s, 3H), 2.30 (s, 3H).

Method AG Compound 795-Methyl-2-(4-(quinoxalin-6-ylmethylamino)-7,8-dihydropyrido[4,3-d]pyrimidin-6(5H)-yl)benzonitrile

A reaction mixture of2-(4-chloro-7,8-dihydropyrido[4,3-d]pyrimidin-6(5H)-yl)-5-methylbenzonitrile(100 mg, 0.35 mmol) and quinoxalin-6-ylmethanamine (150 mg, 0.94 mmol)in acetonitrile (1 mL) and N,N-diisopropylethylamine (500 μL, 3 mmol)was subjected to microwave irradiation at 185° C. for 3.5 h. Thereaction mixture was concentrated and the residue was purified bypreparative HPLC (30-60% acetonitrile-water [10 mM DEA]) to afford alight yellow solid.

LC-MS: 408.2 [M+H]⁺

¹H NMR (400 MHz, d6-DMSO): δ 8.91 and 8.90 (AB, 2H, J=1.8 Hz), 8.29 (s,1H), 8.06 (d, 1H, J=8.6 Hz), 7.97 (d, 1H, J=1.2 Hz), 7.85 (dd, 1H,J=8.6, 1.9 Hz), 7.71 (t, 1H, J=5.8 Hz), 7.60 (d, 1H, J=1.6 Hz), 7.50(dd, 1H, J=8.6, 1.8 Hz), 7.26 (d, 1H, J=8.5 Hz), 4.91 (d, 2H, J=5.8 Hz),4.08 (s, 2H), 3.53 (t, 2H, J=5.6 Hz), 2.87 (t, 2H, J=5.5 Hz), 2.29 (s,3H).

Method AH Compound 805-Methyl-2-(4-(quinolin-2-ylmethylamino)-7,8-dihydropyrido[4,3-d]pyrimidin-6(5H)-yl)benzonitrile

A reaction mixture of2-(4-chloro-7,8-dihydropyrido[4,3-d]pyrimidin-6(5H)-yl)-5-methylbenzonitrile(150 mg, 0.52 mmol) and quinolin-2-ylmethanamine hydrochloride (206.0mg, 1.058 mmol) in acetonitrile (1 mL) and N,N-diisopropylethylamine (1mL, 6 mmol) was subjected to microwave irradiation at 185° C. for 3.5 h.The reaction mixture was concentrated and the residue was purified bypreparative HPLC (30-60% acetonitrile-water [10 mM DEA]) to afford alight yellow solid.

LC-MS: 407.3 [M+H]⁺

¹H NMR (400 MHz, CDCl₃): δ 8.55 (s, 1H), 8.16 (d, 1H, J=8.4 Hz), 8.08(d, 1H, J=8.5 Hz), 7.84 (d, 1H, J=8.1 Hz), 7.74 (t, 1H, J=8.0 Hz), 7.56(t, 1H, J=7.9 Hz), 7.44 (s, 1H), 7.41 (d, 1H, J=8.4 Hz), 7.35 (dd, 1H,J=8.4, 0.94 Hz), 7.05 (d, 1H, J=8.4 Hz), 6.72-6.65 (m, 1H), 4.97 (d, 2H,J=4.0 Hz), 4.24 (s, 2H), 3.65 (t, 2H, J=5.6 Hz), 3.03 (t, 2H, J=5.5 Hz),2.34 (s, 3H).

Method AI Compound 81

2-(4-((1H-Indol-6-yl)methylamino)-7,8-dihydropyrido[4,3-d]pyrimidin-6(5H)-yl)-5-methylbenzonitrile

A reaction mixture of2-(4-chloro-7,8-dihydropyrido[4,3-d]pyrimidin-6(5H)-yl)-5-methylbenzonitrile(100 mg, 0.35 mmol) and 1-(1H-indol-5-yl)-methylamine (139 mg, 0.95mmol) in acetonitrile (1 mL) and N,N-diisopropylethylamine (0.4 mL, 2mmol) was subjected to microwave irradiation at 185° C. for 3 h. Thereaction mixture was concentrated and the residue was purified bypreparative HPLC (30-60% acetonitrile-water [10 mM DEA]) to afford alight yellow solid.

LC-MS: 395.3 [M+H]⁺

¹H NMR (400 MHz, CDCl₃): δ 8.56 (s, 1H), 8.48 (bs, 1H), 7.61 (d, 1H,J=8.1 Hz), 8.39 (s, 1H), 8.38 (s, 1H), 7.28 (dd, 1H, J=8.4, 1.6 Hz),7.21 (t, 1H, J=2.8 Hz), 7.10 (dd, 1H, J=8.1, 1.4 Hz), 6.97 (d, 1H, J=8.4Hz), 6.57-6.50 (m, 1H), 4.82 (d, 2H, J=5.2 Hz), 4.69 (t, 1H, J=5.1 Hz),3.96 (s, 2H), 3.53 (t, 2H, J=5.7 Hz), 3.04 (t, 2H, J=5.6 Hz), 2.29 (s,3H).

Method AJ Compound 822-(4-(Benzo[d][1,3]dioxol-5-ylmethylamino)-7,8-dihydropyrido[4,3-d]pyrimidin-6(5H)-yl)-5-methylbenzonitrile

A reaction mixture of2-(4-chloro-7,8-dihydropyrido[4,3-d]pyrimidin-6(5H)-yl)-5-methylbenzonitrile(100 mg, 0.35 mmol) and piperonylamine (120 mg, 0.79 mmol) inacetonitrile (1 mL) and N,N-diisopropylethylamine (400 μL) was subjectedto microwave irradiation at 185° C. for 3 h. The reaction mixture wasconcentrated and the residue was purified by preparative HPLC (100×20.2mm, C18 column; 30-60% acetonitrile-water [10 mM Et₂NH]) to afford alight yellow solid.

LC-MS: 400.2 [M+H]⁺

¹H NMR (400 MHz, d6-DMSO): δ 8.30 (s, 1H), 7.58 (d, 1H, J=1.5 Hz), 7.49(dd, 1H, J=8.6, 1.6 Hz), 7.40 (t, 1H, J=5.8 Hz), 7.24 (d, 1H, J=8.5 Hz),6.89 (d, 1H, J=1.3 Hz), 6.88-6.75 (m, 2H), 5.96 (s, 2H), 4.55 (d, 2H,J=5.8 Hz), 3.98 (s, 2H), 3.49 (t, 2H, J=5.6 Hz), 2.84 (t, 2H, J=5.5 Hz),2.29 (s, 3H).

Method AK Compounds 89 and 90(R)-2-(4-(1-(Benzo[d][1,3]dioxol-5-yl)ethylamino)-7,8-dihydropyrido[4,3-d]pyrimidin-6(5H)-yl)-5-methylbenzonitrileand(S)-2-(4-(1-(benzo[d][1,3]dioxol-5-yl)ethylamino)-7,8-dihydropyrido[4,3-d]pyrimidin-6(5H)-yl)-5-methylbenzonitrile

A)2-(4-(1-(benzo[d][1,3]dioxol-5-yl)ethylamino)-7,8-dihydropyrido[4,3-d]pyrimidin-6(5H)-yl)-5-methylbenzonitrile

A reaction mixture of2-(4-chloro-7,8-dihydropyrido[4,3-d]pyrimidin-6(5H)-yl)-5-methylbenzonitrile(100 mg, 0.35 mmol) and 1-(benzo[d][1,3]dioxol-5-yl)ethanamine (150 mg,0.91 mmol) in acetonitrile (1 mL) and N,N-diisopropylethylamine (400 μl)was subjected to microwave irradiation at 185° C. for 3 h. The reactionmixture was concentrated and the residue was purified by preparativeHPLC (100×20.2 mm, C18 column; 30-60% acetonitrile-water [10 mM Et₂NH])to afford a light yellow solid.

LC-MS: 413.9 [M+H]⁺;

¹H NMR (400 MHz, d6-DMSO): δ 8.25 (s, 1H), 7.59 (d, 1H, J=1.6 Hz), 7.51(dd, 1H, J=8.6, 1.8 Hz), 7.32 (d, 1H, J=8.4 Hz), 7.00-6.77 (m, 4H), 5.95(d, 2H, J=6.6 Hz), 5.40-5.30 (m, 1H), 4.05 and 3.98 (AB, 2H, J=15.6 Hz),3.55-3.45 (m, 2H), 2.83 (t, 2H, J=5.5 Hz), 2.30 (s, 3H), 1.47 (d, 3H,J=7.0 Hz).

B)(R)-2-(4-(1-(benzo[d][1,3]dioxol-5-yl)ethylamino)-7,8-dihydropyrido[4,3-d]pyrimidin-6(5H)-yl)-5-methylbenzonitrileand(S)-2-(4-(1-(benzo[d][1,3]dioxol-5-yl)ethylamino)-7,8-dihydropyrido[4,3-d]pyrimidin-6(5H)-yl)-5-methylbenzonitrile

Racemic2-(4-(1-(benzo[d][1,3]dioxol-5-yl)ethylamino)-7,8-dihydropyrido[4,3-d]pyrimidin-6(5H)-yl)-5-methylbenzonitrile(70 mg, 0.17 mmol) was resolved by chiral HPLC (CHIRALPAK AD-H column at0° C. [ice-bath], 20×250 mm, hexane/EtOH/Et₂NH [85:15:0.085] at 20mL/min, UV at 240 nm) to afford the title compounds.

(R)-Isomer:

LC-MS: 414.4 [M+H]⁺;

¹H NMR (400 MHz, d6-DMSO): δ 8.25 (s, 1H), 7.59 (d, 1H, J=1.6 Hz), 7.51(dd, 1H, J=8.6, 1.7 Hz), 7.32 (d, 1H, J=8.5 Hz), 7.00-6.77 (m, 4H), 5.95(d, 2H, J=6.6 Hz), 5.40-5.30 (m, 1H), 4.05 and 3.98 (AB, 2H, J=15.6 Hz),3.55-3.45 (m, 2H), 2.83 (t, 2H, J=5.5 Hz), 2.30 (s, 3H), 1.46 (d, 3H,J=7.0 Hz).

(S)-Isomer:

LC-MS: 414.4 [M+H]⁺;

¹H NMR (400 MHz, d6-DMSO): 8.25 (s, 1H), 7.59 (d, 1H, J=1.6 Hz), 7.51(dd, 1H, J=8.6, 1.7 Hz), 7.32 (d, 1H, J=8.4 Hz), 7.00-6.77 (m, 4H), 5.95(d, 2H, J=6.6 Hz), 5.40-5.30 (m, 1H), 4.05 and 3.98 (AB, 2H, J=15.6 Hz),3.55-3.45 (m, 2H), 2.83 (t, 2H, J=5.5 Hz), 2.30 (s, 3H), 1.46 (d, 3H,J=7.0 Hz).

Method AL Compound 915-Methyl-2-(4-(1-(4-methyl-3-(methylsulfonyl)phenyl)ethylamino)-7,8-dihydropyrido[4,3-d]pyrimidin-6(5H)-yl)benzonitrile

A reaction mixture of2-(4-chloro-7,8-dihydropyrido[4,3-d]pyrimidin-6(5H)-yl)-5-methylbenzonitrile(360 mg, 1.26 mmol) and 1-(4-methyl-3-(methylsulfonyl)phenyl)ethanamine(400 mg, 1.88 mmol) in acetonitrile (3 mL) and N,N-diisopropylethylamine(1 mL) was subjected to microwave irradiation at 185° C. for 3.5 h. Thereaction mixture was concentrated and the residue was purified bypreparative HPLC (100×20.2 mm, C18 column; 30-60% acetonitrile-water [10mM Et₂NH]) to afford a light yellow solid (290 mg).

LC-MS: 462.3 [M+H]⁺

¹H NMR (400 MHz, d6-DMSO): δ 8.25 (s, 1H), 7.94 (d, 1H, J=1.8 Hz),7.65-7.55 (m, 2H), 7.51 (dd, 1H, J=8.7, 1.8 Hz), 7.39 (d, 1H, J=8.0 Hz),7.31 (d, 1H, J=8.4 Hz), 7.18 (d, 1H, J=7.6 Hz), 5.52-5.42 (m, 1H), 4.06and 4.01 (AB, 2H, J=15.5 Hz), 3.57-3.42 (m, 2H), 3.19 (s, 3H), 2.83 (t,2H, J=5.4 Hz), 2.59 (s, 3H), 2.30 (s, 3H), 1.52 (d, 3H, J=7.0 Hz).

Method AM Compound 925-Methyl-2-(4-(quinolin-7-ylmethylamino)-7,8-dihydropyrido[4,3-d]pyrimidin-6(5H)-yl)benzonitrile

A reaction mixture of2-(4-chloro-7,8-dihydropyrido[4,3-d]pyrimidin-6(5H)-yl)-5-methylbenzonitrile(480 mg, 1.69 mmol) and quinolin-7-ylmethanamine (400 mg, 2.53 mmol) inacetonitrile (5 mL) and N,N-diisopropylethylamine (1.5 mL, 8.6 mmol) wassubjected to microwave irradiation at 185° C. for 3.5 h. The reactionmixture was concentrated and the residue was purified by semi-prep HPLC(100×20.2 mm, C18 column; 30-60% acetonitrile-water [10 mMdiethylamine]) to yield an off white solid.

LC-MS: 407.3 [M+H]⁺

¹H NMR (400 MHz, d6-DMSO): δ 8.85 (dd, 1H, J=4.0, 1.6 Hz), 8.33 (d, 1H,J=8.0 Hz), 8.29 (s, 1H), 7.93 (d, 1H, J=8.4 Hz), 7.89 (s, 1H), 7.65 (t,1H, J=5.6 Hz), 7.63-7.56 (m, 2H), 7.52-7.45 (m, 2H), 7.26 (d, 1H, J=8.4Hz), 4.87 (d, 2H, J=5.6 Hz), 4.07 (s, 2H), 3.53 (t, 2H, J=5.6 Hz), 2.86(t, 2H, J=5.6 Hz), 2.29 (s, 3H).

Method AN Compounds 93 and 94(R)-2-(4-(1-(4-Chloro-3-(methylsulfonyl)phenyl)ethylamino)-7,8-dihydropyrido[4,3-d]pyrimidin-6(5H)-yl)-5-methylbenzonitrileand(S)-2-(4-(1-(4-chloro-3-(methylsulfonyl)phenyl)ethylamino)-7,8-dihydropyrido[4,3-d]pyrimidin-6(5H)-yl)-5-methylbenzonitrile

A)2-(4-(1-(4-chloro-3-(methylsulfonyl)phenyl)ethylamino)-7,8-dihydropyrido[4,3-d]pyrimidin-6(5H)-yl)-5-methylbenzonitrile

A reaction mixture of2-(4-chloro-7,8-dihydropyrido[4,3-d]pyrimidin-6(5H)-yl)-5-methylbenzonitrile(250 mg, 0.88 mmol) and 1-(4-chloro-3-(methylsulfonyl)phenyl)ethanamine(300 mg, 1.28 mmol) in acetonitrile (2 mL) and N,N-diisopropylethylamine(700 μL) was subjected to microwave irradiation at 185° C. for 3.5 h.The reaction mixture was concentrated and the residue was purified bypreparative HPLC (100×20.2 mm, C18 column; 30-60% acetonitrile-water [10mM Et₂NH]) to afford a light yellow solid.

LC-MS: 482.2 [M+H]⁺

¹H NMR (400 MHz, d6-DMSO): δ 8.25 (s, 1H), 8.08 (d, 1H, J=2.1 Hz), 7.75(dd, 1H, J=8.3, 2.1 Hz), 7.67 (d, 1H, J=8.2 Hz), 7.60 (d, 1H, J=1.6 Hz),7.52 (dd, 1H, J=8.5, 1.8 Hz), 7.30 (d, 1H, J=8.5 Hz), 7.23 (d, 1H, J=7.4Hz), 5.52-5.42 (m, 1H), 4.07 and 4.03 (AB, 2H, J=15.5 Hz), 3.57-3.42 (m,2H), 3.36 (s, 3H), 2.83 (t, 2H, J=5.4 Hz), 2.30 (s, 3H), 1.53 (d, 3H,J=7.1 Hz).

B)(R)-2-(4-(1-(4-chloro-3-(methylsulfonyl)phenyl)ethylamino)-7,8-dihydropyrido[4,3-d]pyrimidin-6(5H)-yl)-5-methylbenzonitrileand(S)-2-(4-(1-(4-chloro-3-(methylsulfonyl)phenyl)ethylamino)-7,8-dihydropyrido[4,3-d]pyrimidin-6(5H)-yl)-5-methylbenzonitrile

Racemic2-(4-(1-(4-chloro-3-(methylsulfonyl)phenyl)ethylamino)-7,8-dihydropyrido[4,3-d]pyrimidin-6(5H)-yl)-5-methylbenzonitrile(100 mg, 0.21 mmol) was resolved by chiral HPLC (CHIRALPAK AD-H columnat ambient, 20×250 mm, hexane/EtOH/Et₂NH [75:25:0.05] at 20 mL/min, UVat 240 nm; 100 mg sample was dissolved in 3 mL EtOH and 3 mL hexane;maximum injection 3 mL) to afford the title compounds.

(R)-Isomer:

LC-MS: 482.3 [M+H]⁺;

¹H NMR (400 MHz, d6-DMSO): δ 8.25 (s, 1H), 8.08 (d, 1H, J=2.1 Hz), 7.75(dd, 1H, J=8.3, 2.1 Hz), 7.67 (d, 1H, J=8.2 Hz), 7.60 (d, 1H, J=1.6 Hz),7.52 (dd, 1H, J=8.5, 1.8 Hz), 7.30 (d, 1H, J=8.5 Hz), 7.23 (d, 1H, J=7.4Hz), 5.52-5.42 (m, 1H), 4.07 and 4.03 (AB, 2H, J=15.5 Hz), 3.57-3.42 (m,2H), 3.36 (s, 3H), 2.83 (t, 2H, J=5.4 Hz), 2.30 (s, 3H), 1.53 (d, 3H,J=7.1 Hz).

(S)-Isomer:

LC-MS: 482.3 [M+H]⁺;

¹H NMR (400 MHz, d6-DMSO): δ 8.25 (s, 1H), 8.08 (d, 1H, J=2.1 Hz), 7.75(dd, 1H, J=8.3, 2.1 Hz), 7.67 (d, 1H, J=8.2 Hz), 7.60 (d, 1H, J=1.6 Hz),7.52 (dd, 1H, J=8.5, 1.8 Hz), 7.30 (d, 1H, J=8.5 Hz), 7.23 (d, 1H, J=7.4Hz), 5.52-5.42 (m, 1H), 4.07 and 4.03 (AB, 2H, J=15.5 Hz), 3.57-3.42 (m,2H), 3.36 (s, 3H), 2.83 (t, 2H, J=5.4 Hz), 2.30 (s, 3H), 1.53 (d, 3H,J=7.1 Hz).

Method AO Compounds 95 and 96(R)-5-Methyl-2-(4-(1-(quinoxalin-6-yl)ethylamino)-7,8-dihydropyrido[4,3-d]pyrimidin-6(5H)-yl)benzonitrileand(S)-5-methyl-2-(4-(1-(quinoxalin-6-yl)ethylamino)-7,8-dihydropyrido[4,3-d]pyrimidin-6(5H)-yl)benzonitrile

A)5-methyl-2-(4-(1-(quinoxalin-6-yl)ethylamino)-7,8-dihydropyrido[4,3-d]pyrimidin-6(5H)-yl)benzonitrile

A reaction mixture of2-(4-chloro-7,8-dihydropyrido[4,3-d]pyrimidin-6(5H)-yl)-5-methylbenzonitrile(200 mg, 0.70 mmol) and 1-(quinoxalin-6-yl)ethanamine (150 mg, 0.87mmol) in acetonitrile (2 mL) and N,N-diisopropylethylamine (734 μL, 4.2mmol) was subjected to microwave irradiation at 185° C. for 3.5 h. Thereaction mixture was concentrated and the residue was purified bypreparative HPLC (100×20.2 mm, C18 column; 30-60% acetonitrile-water [10mM Et₂NH]) to afford a light brown solid (45 mg).

LC-MS: 421.9 [M+H]⁺;

¹H NMR (400 MHz, d6-DMSO): δ 8.91 and 8.89 (AB, 2H, J=1.8 Hz), 8.23 (s,1H), 8.06 (d, 1H, J=8.8 Hz), 8.04 (d, 1H, J=1.6 Hz), 7.94 (dd, 1H,J=8.7, 1.9 Hz), 7.61 (d, 1H, J=1.6 Hz), 7.53 (dd, 1H, J=8.6, 1.7 Hz),7.35 (d, 1H, J=8.5 Hz), 7.30 (d, 1H, J=7.6 Hz), 5.80-5.55 (m, 1H), 4.16and 4.07 (AB, 2H, J=15.5 Hz), 3.57-3.42 (m, 2H), 2.86 (t, 2H, J=4.8 Hz),2.31 (s, 3H), 1.64 (d, 3H, J=7.1 Hz).

B)(R)-5-methyl-2-(4-(1-(quinoxalin-6-yl)ethylamino)-7,8-dihydropyrido[4,3-d]pyrimidin-6(5H)-yl)benzonitrileand(S)-5-methyl-2-(4-(1-(quinoxalin-6-yl)ethylamino)-7,8-dihydropyrido[4,3-d]pyrimidin-6(5H)-yl)benzonitrile

Racemic5-methyl-2-(4-(1-(quinoxalin-6-yl)ethylamino)-7,8-dihydropyrido[4,3-d]pyrimidin-6(5H)-yl)benzonitrile(40 mg, 0.095 mmol) was resolved by chiral HPLC (CHIRALPAK AD-H columnat ambient, 20×250 mm, hexane/EtOH/MeOH [80:10:10] at 20 mL/min, UV at254 nm; 40 mg sample was dissolved in 2 mL EtOH and 2 mL hexane; maximuminjection 1.8 mL) to afford the title compounds.

(R)-Isomer:

LC-MS: 422.5 [M+H]⁺;

¹H NMR (400 MHz, d6-DMSO): δ 8.91 and 8.89 (AB, 2H, J=1.8 Hz), 8.23 (s,1H), 8.06 (d, 1H, J=8.7 Hz), 8.04 (d, 1H, J=1.7 Hz), 7.93 (dd, 1H,J=8.7, 2.0 Hz), 7.61 (d, 1H, J=1.6 Hz), 7.53 (dd, 1H, J=8.6, 1.7 Hz),7.34 (d, 1H, J=8.5 Hz), 7.29 (d, 1H, J=7.6 Hz), 5.75-5.55 (m, 1H), 4.16and 4.07 (AB, 2H, J=15.6 Hz), 3.57-3.42 (m, 2H), 2.86 (t, 2H, J=5.0 Hz),2.31 (s, 3H), 1.64 (d, 3H, J=7.1 Hz).

(S)-Isomer:

LC-MS: 422.5 [M+H]⁺;

¹H NMR (400 MHz, d6-DMSO): δ 8.91 and 8.89 (AB, 2H, J=1.8 Hz), 8.23 (s,1H), 8.06 (d, 1H, J=8.8 Hz), 8.04 (d, 1H, J=1.5 Hz), 7.94 (dd, 1H,J=8.7, 1.9 Hz), 7.61 (d, 1H, J=1.6 Hz), 7.53 (dd, 1H, J=8.6, 1.7 Hz),7.34 (d, 1H, J=8.5 Hz), 7.29 (d, 1H, J=7.6 Hz), 5.72-5.55 (m, 1H), 4.16and 4.07 (AB, 2H, J=15.5 Hz), 3.57-3.42 (m, 2H), 2.86 (t, 2H, J=4.6 Hz),2.31 (s, 3H), 1.64 (d, 3H, J=7.1 Hz).

Assays

Compounds provided herein can be evaluated using cell-based assays, suchas calcium influx or electrophysiological assays, using biochemicalassays, such as binding assays to P2X2 and P2X3 receptors, or can beevaluated in animal models of pain or urinary function. Examples ofassays are described below.

The purinergic receptors P2X2 and P2X3 are expressed in a variety oftissues including various sensory and sympathetic ganglia, such as thedorsal root (DRG), nodose (ND), trigeminal (TG), and superior cervicalganglia (SCG) and also in smooth muscle cells (Burnstock, TrendsPharmacol. Sci. 27:166-76, 2006). In several regions, P2X2 and P2X3receptors are coexpressed and functional studies have demonstrated thepresence of heteromeric P2X2/3 receptors whose properties differ fromthose of either homomeric receptor. In addition, chimeric P2X2/3receptors, containing the N-terminal cytoplasmic domain of P2X2 fused tothe first transmembrane domain of P2X3 have been described; thesechimeric channels retain the pharmacological profile of homomeric P2X3receptors, while gaining the non-desensitizing phenotype of thehomomeric P2X2 receptor (Neelands et al., Br. J. Pharmacol. 140:202-10,2003). The non-desensitizing behavior of the chimeric receptor isespecially useful for screening.

Members of the P2X family are ligand-gated non-selective cation channelswhose activity can be characterized by using electrophysiologicalmethods, or by measuring calcium ion influx using calcium-sensitivefluorescent dyes. Applications of agonists such as ATP, or an ATP analogsuch as α,β-Methyleneadenosine 5′-triphosphate (αβMeATP, Sigma-Aldrich),causes channel opening, resulting in current flow and calcium influx(Bianchi et al., Eur. J. Pharmacol. 376:127-38, 1999).

The compounds provided herein can be tested for antagonist activity atP2X3 and P2X2/3 receptors by measuring their ability to affect channelopening by ATP, αβMcATP, or other agonists. Functional tests of receptoractivity include but are not limited to: (i) calcium ion influx measuredby fluorescence of a calcium-sensitive dye and; (ii) ion flux resultingfrom channel opening measured by electrophysiological methods. Thesemethods can be used to evaluate channel function when the relevantreceptor is heterologously expressed in mammalian or amphibian cells.These methods can also be used to evaluate compounds provided herein inrodent primary neurons and other mammalian primary cells and cell linesthat normally express the receptor of interest.

Compounds can further be evaluated for their ability to bind P2X3 andP2X2/3 receptors using biochemical approaches.

Compounds can also be evaluated for their ability to modify sensory andautonomic nervous system signaling where the receptors are known to havea role (e.g., urinary bladder afferent signaling, sensory nerve painsensation). Finally, compounds provided herein can be tested in vivo inrelevant animal models known to one skilled in the art, such as, forexample, models of neuropathic, inflammatory, or visceral pain, ormodels of urinary incontinence.

The following biological examples are offered to illustrate thecompounds, pharmaceutical compositions and methods provided herein andare not to be construed in any way as limiting the scope thereof.

Calcium Uptake Assay Clones and Cell Lines:

Human P2X3 (Accession no. NM_(—)002559), P2X2 (Accession no.NM_(—)170682) and Rat P2X3 (Accession no. NM_(—)031075) and P2X2(Accession no. NM_(—)053656) are cloned into a mammalian expressionvector (e.g., pcDNA5/TO or pcDNA3 Invitrogen). The human P2X2/3 chimeraclone is created as described by Neelands et al, and then cloned into anexpression vector as above. Receptors are expressed in cells (e.g.,HEK293 or 1321N1 (obtained from the ECACC)) via transient transfectionusing standard lipid mediated transfection, or by creation of stabletransfectants for each receptor. For expression of the P2X2/3heteromeric receptor, the P2X3 expression vector is stably transfectedinto a cell line already stably expressing P2X2. P2X2/3 heteromerfunction is isolated using pharmacological methods. Cell lines aremaintained in DMEM+5% Glutamax, the appropriate level of selectiveantibiotic, and 10% heat inactivated FBS.

P2X Antagonist Assay:

Functional activity of compounds at the P2X receptor is determined bymeasuring their ability to inhibit agonist-induced calcium influx.Compounds are tested for antagonist activity against the P2X2/3 chimera,the P2X3 homomer, or the P2X2/3 heteromer. At the start of eachscreening day, the agonist EC₅₀ is determined. Compound % inhibition orIC₅₀s are subsequently determined using a pre-determined agonistconcentration (EC₅₀₋₉₀ depending on cell line) as a stimulus. Theagonists used are αβMeATP, ATP, or other ATP analogs. Compounds may betested at concentrations ranging from 1 pM to 10 μM.

To test for antagonist activity, cells expressing the appropriatereceptor are seeded onto 96 or 384 well plates 18-24 hours prior toassay. On the day of the assay, cells are loaded with calcium-sensitivefluorescent dye (e.g., Fluo-4 no wash reagent-Invitrogen cat# F36206, orthe BD™ PBX Calcium Assay Kit—BD cat #640175) in Hank's Buffered SaltSolution (HBSS) with up to 10 mM supplemental CaCl₂. Plates areincubated at 37° C. and then equilibrated at room temperature.Antagonism of agonist-induced calcium influx is measured using afluorescent imaging plate reader (e.g. FLIPR^(TETRA), Molecular Devices,Sunnyvale, Calif.). The assay comprises two stages: a pre-treatmentphase followed by a treatment phase. Compounds may be tested as follows:For the pre-treatment phase, 50 μL of 3× concentration of test compoundin HBSS is added to cells containing 100 μL of dye loading media toachieve a final concentration of 1× test compound. For the treatmentphase, at a set interval after pre-treatment (1-30 minutes), 50 μl, of1× test compound plus 4× agonist solution is added, resulting in a finalconcentration of 1× compound and 1× agonist. Fluorescence is measured at0.1-3 second intervals—with an excitation wavelength of 494 nM and anemission wavelength of 515 nM. Responses are measured as (peakfluorescence after agonist addition) minus (baseline fluorescence priorto treatment). Percent inhibition is calculated as follows:

${{Percentage}\mspace{14mu} {inhibition}} = {1 - {\frac{\begin{pmatrix}{{{Compound}\mspace{14mu} {Response}} -} \\{{Control}\mspace{14mu} {Resonse}}\end{pmatrix}}{\begin{pmatrix}{{{Agonist}\mspace{14mu} {Response}} -} \\{{Control}\mspace{14mu} {Response}}\end{pmatrix}} \times 100}}$

IC₅₀ values are determined by analyzing dose response data in a 4parameter logistic fit using GraphPad Prizm.

Electrophysiological Experiments Whole Cell Patch Clamp:

Whole cell recordings are made using the Multiclamp700A patch-clampamplifier and Clampex acquisition program (Molecular DevicesCorporation). Whole-cell recordings are obtained from 1321N1 or HEKcells stably or transiently transfected with P2X3 and/or P2X2 expressionvectors. Solutions are either applied for periods of 1 to 3 s by agravity flow, 8-valve delivery system, or for periods of millisecondsusing the quick-change Dynaflow perfusion system (Cellectricon Inc.).The internal pipette solution may include 140 mM Cesium-Chloride, 10 mMEGTA, and 5 mM Hepes at pH 7.2; normal external solution is 140 mM NaCl,5 mM KCl, 1 mM CaCl₂, 2 mM MgCl₂, 25 mM Hepes, and 10 mM glucose.Concentration-response curves are obtained by recording currents inresponse to brief applications of agonist at 1-3 min intervals whereregular external solution is perfused during the intervals. To obtaininhibition curves, antagonists are pre-applied to the cells for adefined time period before a short application of theagonist+antagonist. The periods of antagonist pre-application andagonist+antagonist applications are constant for the entire testconcentration series. Agonist evoked currents are measured in cells thatare voltage clamped at −60 or −80 millivolts. IC₅₀ values are determinedby analyzing dose response data in a 4 parameter logistic fit usingGraphPad Prizm or Origin.

Automated Two-Electrode Voltage Clamp Recording:

Xenopus oocytes (Nasco) are isolated by enzymatic dissociation usingcollagenase (Worthington, 2 mg/ml). Oocytes are then individuallyinjected with P2X3, P2X2, or a combination of P2X2 and P2X3 mRNA. Eachoocyte receives ˜64 nL of RNA solution in water at a concentration of˜0.01 μg/μL. Injected oocytes are stored in standard oocyte incubationsolution, ND96, containing (in mM) 96 NaCl, 2 KCl, 1 MgCl₂, 1-5 CaCl₂and 50 μg/mL Gentamicin at 16° C. Agonist-induced-current caused by P2Xchannel opening is observed in oocytes 1-5 days after injection. Forautomated recordings, 8 oocytes are placed in the recording chambers.Each oocyte is impaled by 2 glass electrodes having resistances of 0.5to 1 MOhm when filled with a 3 M KCl solution. Electrode advancement andoocyte impalement are under software control (OPUSXPRESS 1.1, Moleculardevices Corporation). The solutions are prepared in 96 well plates androbotically pipetted into the oocyte recording chambers by an 8 channelpipettor. Inhibition by antagonists is determined by calculating %current remaining when oocytes are stimulated with agonist in thepresence of test compound compared to the peak current in the presenceof agonist alone. The sequence of solution application to the oocyte isas follows: a specific concentration (e.g., EC₅₀, EC₈₀, or EC₉₀) of theagonist is added first to elicit the maximal response. After the pulse,oocytes are washed for several minutes with ND96. The test compound isthen added at a particular concentration, followed by the compound atthe same concentration along with the agonist. Concentrations for thecompounds may range from 0.3 to 10,000 nM. IC₅₀ values are determined byanalyzing dose response data using a 4 parameter logistic fit usingGraphPad Prizm or Origin software.

Manual Two-Electrode Voltage Clamp:

Individual oocytes are impaled manually with 2 electrodes and agonistevoked current are measured using an Oocyte clamp amplifier (WarnerInstrument Corp.) and Clampex (Molecular Devices Corporation)acquisition software. Solutions are delivered using gravity flow andapplied as above. The agonist induced current is measured in the absenceand presence of antagonist. Antagonists are tested in a concentrationseries to obtain an inhibition curve as described above.

Selectivity Screens:

Compounds that inhibit P2X3 and/or P2X2/3 activation will be tested foractivity against other P2X receptors to determine their selectivity forspecific P2X family members. The list of receptors to be assayedincludes, but is not restricted to P2X1, P2X2, P2X4, P2X5, P2X6, andP2X7. The types of assay used for selectivity determination mayinclude: 1) Agonist-induced Calcium influx in cells heterologouslyexpressing the relevant receptor, 2) Electrophysiological determinationof receptor inhibition in either mammalian cells or Xenopus oocytesheterologously expressing the receptor of interest. Methods and dataanalysis are similar to those described above for P2X3 and P2X2/3.

Radioligand Binding:

Radioligand experiments are done to determine the affinity of testcompounds for P2X3 homomeric and P2X2/3 heteromeric receptors. Thesestudies also provide valuable insights into the mechanism of action ofantagonism. The general methodologies used for radioligand bindingexperiments for P2X3 and P2X2/3 receptors are described by Jarvis etal., J. Pharmacol. Exp. Ther. 10:407-16, 2004.

Briefly, cell membranes are prepared from cells transiently or stablyexpressing P2X3 or P2X2/3 receptors. Cells are grown to confluence,washed, isolated, and stored as pellets at −80° C. until use. Somestudies may require the addition of Apyrase or hexokinase(Sigma-Aldrich) during membrane preparation to minimize ATP-mediatedreceptor desensitization during membrane preparation. Membranes areprepared by resuspending the cell pellet in homogenization buffer,homogenizing, and centrifuging to obtain a membrane pellet. Totalprotein concentrations are determined using standard methods.

Displacement binding studies are conducted using procedures adapted fromJarvis et al. Under optimized conditions, ligand competition experimentsare conducted using radioligand ([³H]A-317491, Abbott), or other highaffinity radioligands and a range of different concentrations of testcompounds in binding buffer. Ligand saturation studies are conductedusing a range of concentrations of radioligand. All binding reactionsare terminated by rapid filtration through a glass fiber filter.Membranes are washed, incubated in scintillant, and counted in ascintillation counter. IC₅₀ values are determined using a four-parameterlogistic Hill equation.

Drug Metabolism and Pharmacokinetics Caco-2 Permeability:

-   Caco-2 permeability is measured according to the method described in    Yee, Pharm. Res. 14:763-6, 1997. Caco-2 cells are grown on filter    supports (Falcon HTS multiwell insert system) for 14 days. Culture    medium is removed from both the apical and basolateral compartments    and the monolayers are preincubated with pre-warmed 0.3 mL apical    buffer and 1.0 mL basolateral buffer for 0.75 hour at 37° C. in a    shaker water bath at 50 cycles/min. The apical buffer consists of    Hanks Balanced Salt Solution, 25 mM D-glucose monohydrate, 20 mM MES    Biological Buffer, 1.25 mM CaCl₂ and 0.5 mM MgCl₂ (pH 6.5). The    basolateral buffer consists of Hanks Balanced Salt Solution, 25 mM    D-glucose monohydrate, 20 mM HEPES Biological Buffer, 1.25 mM CaCl₂    and 0.5 mM MgCl₂ (pH 7.4). At the end of the preincubation, the    media is removed and test compound solution (10 μM) in buffer is    added to the apical compartment. The inserts are moved to wells    containing fresh basolateral buffer and incubated for 1 hr. Drug    concentration in the buffer is measured by LC/MS analysis.

Flux rate (F, mass/time) is calculated from the slope of cumulativeappearance of substrate on the receiver side and apparent permeabilitycoefficient (Papp) is calculated from the following equation:

Papp (cm/sec)=(F*VD)/(SA*MD)

where SA is surface area for transport (0.3 cm²), VD is the donor volume(0.3 mL), MD is the total amount of drug on the donor side at t=0. Alldata represent the mean of 2 inserts. Monolayer integrity is determinedby Lucifer Yellow transport.

Human Dofetilide Binding:

Cell paste of HEK-293 cells expressing the HERG product can be suspendedin 10-fold volume of 50 mM Tris buffer adjusted at pH 7.5 at 25° C. with2 M HCl containing 1 mM MgCl₂, 10 mM KCl. The cells are homogenizedusing a Polytron homogenizer (at the maximum power for 20 seconds) andcentrifuged at 48,000 g for 20 minutes at 4° C. The pellet isresuspended, homogenized and centrifuged once more in the same manner.The resultant supernatant is discarded and the final pellet wasresuspended (10-fold volume of 50 mM Tris buffer) and homogenized at themaximum power for 20 seconds. The membrane homogenate is aliquoted andstored at −80° C. until use. An aliquot is used for proteinconcentration determination using a Protein Assay Rapid Kit and ARVO SXplate reader (Wallac). All the manipulation, stock solution andequipment are kept on ice at all time. For saturation assays,experiments are conducted in a total volume of 200 μL. Saturation isdetermined by incubating 20 μl of [³H]-dofetilide and 160 μl of membranehomogenates (20-30 μg protein per well) for 60 min at room temperaturein the absence or presence of 10 μM dofetilide at final concentrations(20 μL) for total or nonspecific binding, respectively. All incubationsare terminated by rapid vacuum filtration over polyetherimide (PEI)soaked glass fiber filter papers using Skatron cell harvester followedby two washes with 50 mM Tris buffer (pH 7.5 at 25° C.). Receptor-boundradioactivity is quantified by liquid scintillation counting usingPackard LS counter.

For the competition assay, compounds are diluted in 96 wellpolypropylene plates as 4-point dilutions in semi-log format. Alldilutions are performed in DMSO first and then transferred into 50 mMTris buffer (pH 7.5 at 25° C.) containing 1 mM MgCl₂, 10 mM KCl so thatthe final DMSO concentration became equal to 1%. Compounds are dispensedin triplicate in assay plates (4 μL). Total binding and nonspecificbinding wells are set up in 6 wells as vehicle and 10 μM dofetilide atfinal concentration, respectively. The radioligand is prepared at 5.6×final concentration and this solution is added to each well (36 μL). Theassay is initiated by addition of YSi poly-L-lysine ScintillationProximity Assay (SPA) beads (50 μL, 1 mg/well) and membranes (110 μL, 20μg/well). Incubation is continued for 60 min at room temperature. Platesare incubated for a further 3 hours at room temperature for beads tosettle. Receptor-bound radioactivity is quantified by counting WALLACMICROBETA plate counter.

HERG Assay:

HEK 293 cells which stably express the HERG potassium channel are usedfor electrophysiological study. The methodology for stable transfectionof this channel in HEK cells can be found elsewhere (Zhou et al.,Biophys. J. 74:230-41, 1998). Before the day of experimentation, thecells are harvested from culture flasks and plated onto glass coverslipsin a standard Minimum Essential Medium (MEM) medium with 10% Fetal CalfSerum (FCS). The plated cells are stored in an incubator at 37° C.maintained in an atmosphere of 95% O₂/5% CO₂. Cells are studied between15-28 hrs after harvest.

HERG currents are studied using standard patch clamp techniques in thewhole-cell mode. During the experiment the cells are superfused with astandard external solution of the following composition (mM); NaCl, 130;KCl, 4; CaCl₂, 2; MgCl₂, 1; Glucose, 10; HEPES, 5; pH 7.4 with NaOH.Whole-cell recordings are made using a patch clamp amplifier and patchpipettes which have a resistance of 1-3 MOhm when filled with thestandard internal solution of the following composition (mM); KCl, 130;MgATP, 5; MgCl₂, 1.0; HEPES, 10; EGTA 5, pH 7.2 with KOH. Only thosecells with access resistances below 15 MOhm and seal resistances >1 GOhmare accepted for further experimentation. Series resistance compensationwas applied up to a maximum of 80%. No leak subtraction is done.However, acceptable access resistance depends on the size of therecorded currents and the level of series resistance compensation thatcan safely be used. Following the achievement of whole cellconfiguration and sufficient time for cell dialysis with pipettesolution (>5 min), a standard voltage protocol is applied to the cell toevoke membrane currents. The voltage protocol is as follows. Themembrane is depolarized from a holding potential of −80 mV to +40 mV for1000 ms. This was followed by a descending voltage ramp (rate 0.5 mVmsec-1) back to the holding potential. The voltage protocol is appliedto a cell continuously throughout the experiment every 4 seconds (0.25Hz). The amplitude of the peak current elicited around −40 mV during theramp is measured. Once stable evoked current responses are obtained inthe external solution, vehicle (0.5% DMSO in the standard externalsolution) is applied for 10-20 min by a peristalic pump. Provided thereare minimal changes in the amplitude of the evoked current response inthe vehicle control condition, the test compound of either 0.3, 1, 3, 10mM is applied for a 10 min period. The 10 min period includes the timewhich supplying solution is passing through the tube from solutionreservoir to the recording chamber via the pump. Exposing time of cellsto the compound solution is more than 5 min after the drug concentrationin the chamber well reaches the attempting concentration. There is asubsequent wash period of a 10-20 mM to assess reversibility. Finally,the cells are exposed to high dose of dofetilide (5 mM), a specific IKrblocker, to evaluate the insensitive endogenous current.

All experiments are performed at room temperature (23±1° C.). Evokedmembrane currents are recorded on-line on a computer, filtered at 500-1KHz (Bessel −3 dB) and sampled at 1-2 KHz using the patch clampamplifier and specific data analyzing software. Peak current amplitude,which occurs at around −40 mV, is measured off line on the computer.

The arithmetic mean of the ten values of amplitude is calculated undervehicle control conditions and in the presence of drug. Percent decreaseof IN in each experiment was obtained by the normalized current valueusing the following formula: IN=(1−ID/IC)×100, where ID is the meancurrent value in the presence of drug and IC is the mean current valueunder control conditions. Separate experiments are performed for eachdrug concentration or time-matched control, and arithmetic mean in eachexperiment is defined as the result of the study.

Half-Life in Human Liver Microsomes (HLM):

Test compounds (1 μM) are incubated with 3.3 mM MgCl₂ and 0.78 mg/mL HLM(HL101) in 100 mM potassium phosphate buffer (pH 7.4) at 37° C. on a96-deep well plate. The reaction mixture is split into two groups, anon-P450 and a P450 group. NADPH is only added to the reaction mixtureof the P450 group. An aliquot of samples of P450 group is collected at0, 10, 30, and 60 min time point, where 0 min time point indicates thetime when NADPH is added into the reaction mixture of P450 group. Analiquot of samples of non-P450 group is collected at −10 and 65 min timepoint. Collected aliquots are extracted with acetonitrile solutioncontaining an internal standard. The precipitated protein is spun downin a centrifuge (2000 rpm, 15 min). The compound concentration in thesupernatant is measured by LC/MS/MS system. The half-life value isobtained by plotting the natural logarithm of the peak area ratio ofcompounds/internal standard versus time. The slope of the line of bestfit through the points yields the rate of metabolism (k). This isconverted to a half-life value using following equation:

Half-life=ln 2/k.

In Vivo Efficacy Assays

P2X3, P2X2/3 antagonists may be tested in various animal models of humandiseases, including models of neuropathic, inflammatory, and visceralpain, and models of bladder function. P2X3 antagonists may beadministered prior to or post-induction of the model depending upon thespecific model and the compound PK characteristics. The route ofadministration may include intraperitoneal, (i.p.), subcutaneous (s.c.),oral (p.o.), intravenous (i.v.), intrathecal (i.t.), or intraplantar.The endpoints for these studies may include mechanical allodynia,thermal hyperalgesia, cold allodynia, decreased formalin-induced painresponses, decreased writhing and contractions or altered bladdermechanosensation as appropriate for the model as described below.

Formalin Model:

Test compounds are administered at various times prior to intraplantaradministration of formalin. A dilute solution of formalin (25-50 μL of1-2.5% formaldehyde/saline) is administered s.c. into the plantarsurface of the left hind paw under light restraint. Immediatelyfollowing injection, animals are placed on a mesh stand inside a clearobservation chamber large enough to allow for free movement of theanimals during the study. Behaviors are scored using manual scoring orautomated scoring.

Manual scoring: Using a three channel timer, the observer records thetime (t in seconds) of decreased weight-bearing (t₁), paw lifting (t₂),and licking/biting/shaking (t₃). Results are weighted according to themethod of Dubuisson and Dennis, Pain, 4:161-174, 1977, using the formulat₁+2t₂+3t₃/180 where 180 s is the evaluation time for each increment.Behaviors are acquired in alternating 3 min increments starting attime=0 min (i.e. 0-3 min, 6-9 min etc.) and ending at 60 min.

Automated scoring: A small metal band weighing 0.5 g is placed on theleft paw. Formalin is administered and the animal placed unrestrainedinside an observation chamber over an electromagnetic detector system(Automated Nociception Analyzer, University of California, San Diego).The number of paw flinches is electronically recorded.

ATP and αβ-methylene ATP (αβ meATP)-Induced Inflammatory Pain:

Rats are administered up to 1 μMol αβmeATP, ATP, adenosine, or PBS in avolume up to 100 μL subcutaneously into the dorsal surface of thehindpaw. Immediately after injection, animals are placed on a standinside a clear observation chamber large enough to allow for freemovement of the animals. The duration of flinching and licking arerecorded over a 20 minute interval to evaluate nocifensive behavior.Responses are measured using the either the manual or automated methodsdescribed above for the Formalin test. Additional behavioral testing mayinclude assessment of mechanical allodynia and thermal hyperalgesia. Fortesting, compounds are administered prior to agonist injection.

Complete Freund's Adjuvant Model (CFA):

Animals receive an s.c. injection of 100 μL complete Freund's adjuvantcontaining 100 μg Mycobacterium tuberculosis strain H37Ra into theplantar surface of the right hind paw under isoflurane anesthesia.Swelling and inflammation are visible within 1 h after administration.Nociceptive testing may begin 24 h post CFA administration. Compoundsare generally administered 0.5-12 hrs before testing.

Carageenan Induced Acute Pain:

Animals receive a subcutaneous injection of 100 μL of 2% carrageenaninto the plantar surface of the right hind paw under isofluraneanesthesia. Swelling and inflammation are visible within 1 h afteradministration. Nociceptive testing may start 3-24 h post carageenanadministration (Hargreaves et al., Pain, 32:77-88, 1988). Compounds aregenerally administered 0.5-12 hrs before testing.

Chronic Constriction Injury Model (CCI or Bennett Model):

The CCl model is performed according to the method described by Bennettand Xie, Pain, 33:87-107, 1988. Briefly, under isoflurane anesthesia,the right sciatic nerve is exposed at mid-thigh level via bluntdissection through the biceps femoris. Proximal to the bifurcation ofthe sciatic nerve, about 7 mm of nerve is freed of adhering tissue and 4loose ligatures of 4.0 chromic gut are tied around the nerve. Spacingbetween ligatures is approximately 1 mm. The wound is closed in layers,and the skin closed with staples or non-silk sutures. Sham operatedanimals are treated identically with the exception that the sciaticnerve will not be ligated. Nociceptive testing can be done 7-21 dayspost surgery. Compounds are generally administered 0.5-12 hrs beforetesting.

Spinal Nerve Transection (SNT or Chung Model):

Under pentobarbital anesthesia (60 mg/kg, i.p.), rats are placed in aprone position on a flat, sterile surface. A midline incision from L4-S2is made and the left paraspinal muscles are separated from the spinousprocesses. The L5 and L6 spinal nerves are tightly ligated with a 4-0silicon-treated silk suture, according to the method described by Kimand Chung, Pain, 50:355-363, 1992. The L4 spinal nerve is carefullypreserved from being surgically injured. The skin is closed with woundclips and animals are returned to their home cages. Rats exhibitingprolonged postoperative neurological deficits or poor grooming areexcluded from the experiments. The animals are assessed for nociceptiveresponses prior to surgery (baseline), then at various timepoints afteradministration of test compounds. Nociceptive testing can be done 7-21days post surgery. Compounds are generally administered 0.5-12 hrsbefore testing.

Chemotherapy-Induced Painful Neuropathy:

Chemotherapy neuropathy is induced by i.p. administration of 1 mg/kgTaxol administered once/day on 4 alternating days (total dose=4 mg/kg)(Polomano et al., Pain, 94:293-304, 2001). Nociceptive testing can bedone 9-30 days after the start of Taxol administration. Compounds aregenerally administered 0.5-12 hrs before testing.

Nociceptive Testing:

Mechanical Allodynia: Mechanical allodynia testing is performed usingthe up-down method of Dixon, Ann. Rev. Pharmacol. Toxicol. 20:441-462,1980, modified for mechanical thresholds by Chaplan et al., J. Neurosci.Methods 53:55-63, 1994. To assess tactile allodynia, rats are placed inclear, plexiglass compartments with a wire mesh floor and allowed tohabituate for a period of at least 15 minutes. After habituation, aseries of von Frey monofilaments are presented to the plantar surface ofthe left (operated) foot of each rat. Each presentation lasts for aperiod of 4-8 seconds or until a nociceptive withdrawal behavior isobserved. Flinching, paw withdrawal or licking of the paw are considerednociceptive behavioral responses. The 50% withdrawal threshold will becalculated using the method described by Chaplan et al., J. Neurosci.Methods 53:55-63, 1994

Thermal Hyperalgesia: Hind paw withdrawal latencies to a noxious thermalstimulus are determined using a plantar test apparatus (Ugo Basile)following the technique described by Hargreaves et al., Pain 32: 77-88,1988. The radiant heat sourced is focused onto the plantar surface ofthe ipsilateral paw, and the paw withdrawal latency is determined. Anincrease latency of paw withdrawal demonstrates reversal ofhyperalgesia. Mechanical Hyperalgesia: The paw pressure assay can beused to assess mechanical hyperalgesia. For this assay, hind pawwithdrawal thresholds (PWT) to a noxious mechanical stimulus aredetermined using an analgesymeter (Ugo Basile) as described in Stein etal., Pharmacol. Biochem. Behav. 31:451-455, 1988.

Mechanical Hyperalgesia: The paw pressure assay can be used to assessmechanical hyperalgesia. For this assay, hind paw withdrawal thresholds(PWT) to a noxious mechanical stimulus are determined using ananalgesymeter (Ugo Basile) as described in Stein et al., Pharmacol.Biochem. Behav. 31:451-455, 1988. The maximum weight that can be appliedto the hind paw is set at 250 g and the end point is taken as completewithdrawal of the paw. PWT is determined once for each rat at each timepoint and only the affected (ipsilateral) paw is tested.

Cold allodynia: To measure cold allodynia, a drop of acetone is appliedto the plantar surface of the paw through the underside of the gratingon which the animals are standing using a 50 μL Hamilton syringe. Theprocess is performed 5 times with a 3 min interval between each time.Vigorous shaking will be recorded as a positive response, and the timespent shaking is recorded. Alternatively, cold allodynia may be testedusing the cold water bath method in which animals are placed into a coldwater bath with water at a depth of 1.5-2.0 cm and at a temperature of3-4 degrees centigrade and the number of paw lifts counted.

Colo-Rectal Distension (CRD):

Prior to induction of the model, animals are deprived of food butallowed access to water ad libitum for 16 h prior to the induction ofthe model. A 5 cm latex balloon is attached to a barostat systemcomposed of a flow meter and pressure control program by a length oftubing. Under isoflurane anesthesia, the balloon is inserted into thedistal colon via the anus at a distance of 5 cm from the anus and tapedto the base of the tail. Post-anesthesia, the animal is placedunrestrained into a clean polypropylene cage and allowed to acclimatefor 30 mins. The balloon is progressively inflated from 0-75 mmHg in 5mm increments every 30 seconds. The colonic reaction threshold isdefined as the pressure inducing the first abdominal contraction.Abdominal contraction indicative of visceral pain correlates withhunching, hump-backed position, licking of the lower abdomen, repeatedwaves of contraction of the ipsilateral oblique musculature with inwardturning of the ipsilateral hindlimb, stretching, squashing of the lowerabdomen against the floor (Wesselman, Neurosci. Lett., 246:73-76, 1998).Alternatively, electrodes may be placed into the external obliquemusculature for eletromyographic recordings of abdominal contractions.In this case, EMG activity is quantified during colonic ballooninflation. Compounds are generally administered 0.5-12 hrs beforetesting.

Acetic Acid Writhing Test:

A 0.6% solution of acetic acid (10 mL/kg) is administered i.p. to ratsand the number of abdominal constrictions within 30 min are counted.Compounds are generally administered 0.5-12 hrs before testing.

Bladder Afferent Nerve Recordings:

In order to determine the precise role of inhibition of P2X3 and P2X2/3receptors in the micturition response, test compounds will be examinedfor their ability to modulate afferent signaling from the urinarybladder. Compounds are evaluated in the urinary bladder/pelvic nervepreparation described by Vlaskovska et al., J. Neuroscience, 21:5670-7,2001, and Cockayne et al., J. Physiol. 567:621-39, 2005. Briefly, thewhole urinary tract attached to the lower vertebrae and surroundingtissues is isolated en bloc and superfused in a recording chamber withoxygenated (5% CO₂ and 95% O₂) Krebs solution. The bladder iscatheterized through the urethra for intraluminal infusion. A seconddouble lumen catheter is inserted into the bladder to measureintraluminal pressure and to drain the bladder. After the bladder isprepared, the pelvic nerve exiting the vertebrae is dissected andimpaled with a suction glass electrode. Nerve activity is measured usingstandard electrophysiological methods. Following a 60 min stabilizationperiod, repeated ramp distensions are performed until the afferentresponse stabilizes. This stabilized afferent response was used forcomparing mechanosensitivity of bladder afferents between differenttreatment groups.

Isovolumetric Bladder Contraction Assay:

Female Sprague-Dawley rats are anesthetized, tracheotomized, andcannulated in the carotid artery and femoral vein. The urinary bladderis accessed via an abdominal incision, and the ureters ligated andtransected. For fluid infusion and pressure measurements, the urinarybladder is cannulated.

Post surgery, the bladder is infused with saline until stablevolume-induced bladder contractions are elicited. Once stable thresholdvolumes and contraction frequencies are obtained, the animal is dosedwith compound and contraction frequency is measured.

Refill and Cystitis Models of Bladder Function:

Animals are anaesthetized, and transurethral closed cystometry wasconducted as previously described (Dmitrieva et al., Neuroscience78:449-59, 1997; Cockayne et al., Nature 407:1011-5, 2000). The bladderis catheterized transurethrally with a PE-10 polypropylene catheter.Each cystometrogram consists of slowly filling the bladder with normalsaline via the transurethral catheter, and then recording the pressureassociated with filling via a pressure transducer. Contractions greaterthan a predetermined threshold value are interpreted as micturitioncontractions. For each cystometrogram, the volume at which activecontractions occurred (micturition threshold) and the number ofcontractions per cystometrogram are recorded. The effects of compoundsare then determined.

Cystometrograms may also be obtained in animal cystitis models in whichbladders are irritated by injection of cyclophosphamide (150 mg/kg,i.p.) 24 hrs prior to cystometry, or by infusion of up to 1% acetic acidduring cystometry.

The synthetic and biological examples described in this application areoffered to illustrate the compounds, pharmaceutical compositions andmethods provided herein and are not to be construed in any way aslimiting their scope. In the examples, all temperatures are in degreesCelsius (unless otherwise indicated). Compounds that can be prepared inaccordance with the methods provided herein along with their biologicalactivity data are presented in following Table. The syntheses of theserepresentative compounds are carried out in accordance with the methodsset forth above.

Exemplary Compounds Provided Herein

The following compounds can be prepared according to the syntheticmethods described herein. A calcium uptake assay was performed asdescribed above and the results are shown in Table 1 wherein theactivity of each compound is expressed in Table 1 as follows:

TABLE 1 Exemplary 2-Cyanophenyl Fused Heterocyclic Compounds P2X3 P2X2/3MS IC₅₀ IC₅₀ ID STRUCTURE MW (obsd) (nM) (nM) 1

424.43 425.2 19 92 2

489.3 491.1 80 3

450.47 451 870 4

444.85 444.7 37 842 5

478.4 479.3 1840 6

503.32 505 42 455 7

438.45 439.2 22 42 8

458.87 459.1 25 383 9

428.39 429.6 85 11432 10

410.4 411.2 63 1814 11

458.87 459 187 >10000 12

419.92 420.5 628 1190 13

406.88 407.1 59 169 14

451.33 453.1 78 325 15

386.46 387.4 9 27 16

479.29 481.1 91 1128 17

444.85 445.3 118 4886 18

521.02 521.4 >10000 >10000 19

464.91 1379 >10000 20

488.9 489.2 90 903 21

414.51 415.5 12 31 22

450.49 451.2 13 43 23

416.48 417.5 6 28 24

430.51 431.3 14 20 25

468.48 469.4 55 136 26

430.51 431.2 43 397 27

390.88 391.4 11 25 28

390.88 391.4 29 152 29

356.43 357.3 196 1674 30

396.5 397.3 236 377 31

386.46 387.5 16 92 32

425.32 425.3 41 50 33

384.48 385.3 38 127 34

450.93 451.3 33 105 35

436.9 437.4 23 200 36

380.45 381.3 183 1093 37

395.47 396.4 18 33 38

396.45 397.4 15 45 39

371.45 372.2 12 82 40

436.52 437.4 21 92 41

444.49 207 1676 42

443.51 444.4 26 174 43

471.56 472.5 302 2211 44

415.89 416.4 122 753 45

391.86 392.4 28 246 46

454.45 455.2 21 71 47

474.87 475.4 54 671 48

387.46 388.1 89 124 49

415.56 416.3 474 925 50

456.94 457.1 31 63 51

442.91 443.5 284 1015 52

477.36 476.8 41 286 53

422.49 423.4 65 324 54

402.46 403 32 62 55

495.36 496.4 512 1296 56

394.48 395 63 82 57

421.89 422.4 34 1724 58

401.47 402 10 164 59

447.56 448.6 16 55 60

417.47 418.4 14 130 61

399.5 400.4 101 1346 62

470.91 471.3 32 273 63

454.58 455.4 96 1121 64

468.48 469.4 23 59 65

468.48 469.3 806 5419 66

385.47 386.1 14 30 67

385.47 385.9 486 3797 68

387.44 388.3 13 42 69

407.86 407.8 42 224 70

436.46 437.3 7 33 71

467.98 468.4 37 120 72

456.88 457.2 16 404 73

421.89 422.5 15 225 74

401.47 402.3 7 61 75

405.89 406.3 15 180 76

467.98 468.4 40 241 77

510.52 511.2 130 536 78

437.89 438.2 42 854 79

407.48 408.2 34 67 80

406.49 407.3 156 263 81

394.48 395.3 423 2163 82

399.45 400.3 56 310 83

413.48 413.9 54 125 84

427.9 428.2 125 478 85

371.45 372.2 37 663 86

421.51 421.9 75 276 87

401.47 401.8 481 5363 88

482.01 482.2 36 19 89

413.48 414.4 15 19 90

413.48 414.4 2206 7074 91

461.59 462.3 23 45 92

406.49 407.3 20 24 93

482.01 482.3 17 12 94

482.01 482.3 430 4546 95

421.51 422.5 15 45 96

421.51 422.5 570 >10000

Pharmacokinetic Evaluation of Compounds Following Intravenous and OralAdministration in Rats.

Male Sprague-Dawley rats are acclimatized for at least 24 hours prior toexperiment initiation. During the acclimation period, all animalsreceive food and water ad libitum. However, food but not water isremoved from the animal's cages at least 12 hours before initiation ofthe experiment. During the first 3 hours of experimentation, the animalsreceive only water ad libitum. At least three animals each are testedfor intravenous and oral dosage. For intravenous formulation, compoundsare dissolved (0.25 to 1 mg/mL) in a mixture of 3% dimethyl sulfoxide,40% PEG 400 and the rest percentage of 40% Captisol in water (w/v). Theanimals are weighed before dosing. The determined body weight is used tocalculate the dose volume for each animal.

Dose volume (mL/kg)=1 mg/kg/formulation concentration (mg/mL)

In instances where the formulation concentrations are less than 0.5mg/mL, the dosing volume is about 2 mL/kg.

For oral formulation, compounds of this invention are suspended (0.5 to0.75 mg/mL) in a mixture of 5% of 10% Tween 80 in water (v/v) and 95% of0.5% methyl cellulose in water (w/v). PO rats are typically dosedthrough oral gavage following the same dose volume formula as IV toachieve a dose level of 1 to 5 mg/kg. For IV dosing, blood samples arecollected (using a pre-heparinized syringe) via the jugular veincatheter at 2, 5, 15, 30, 60, 120, 180, 300, 480, and 1440 minutes postdosing. For PO dosing, blood samples are collected (using apre-heparinized syringe) via the jugular vein catheter before dosing andat 5, 15, 30, 60, 120, 180, 300, 480, and 1440 minutes post dosing.About 250 μL of blood is obtained at each time point from the animal.Equal volumes of 0.9% normal saline are replaced to prevent dehydration.The whole blood samples are maintained on ice until centrifugation.Blood samples are then centrifuged at 14,000 rpm for 10 minutes at 4° C.and the upper plasma layer transferred into a clean vial and stored at−80° C. The resulting plasma samples are then analyzed by liquidchromatography-tandem mass spectrometry. Following the measurement ofplasma samples and dosing solutions, plasma concentration-time curve isplotted. Plasma exposure is calculated as the area under theconcentration-time curve extrapolated to time infinite (AUC_(inf)). TheAUC_(inf) is averaged and the oral bioavailability (% F) for individualanimal is calculated as:

AUC_(inf)(PO)/AUC_(inf)(IV), normalized to their respective dose levels.

The % F can be reported as the mean % F of all animals dosed orally withthe compound of the invention at the specified level.

Plasma Protein Binding

The plasma protein binding of compounds of invention is measured inhuman and rat plasma, respectively. A stock solution of the testedcompound is prepared in 1 mg/mL in DMSO solution. The stock solution isspiked into the blank plasma to get a final compound concentration at 1μg/mL for testing. Equilibrium dialysis (The equilibrium dialyzer-96™MWCO 5K Daltons, Harvard Apparatus) method is used for the testingpurpose.

The compound spiked plasma (at 1 μg/mL) and phosphate buffer (0.1 M, pH7.4), 200 μl each, are added into the opposite sides of the membrane ina 96-well equilibrium dialyzer, respectively. The dialyzer plate iscovered and incubated overnight (16 hr) at 37° C. in the 8-plate rotorincubator (Big Shot III 8-plate rotor, Harvard Apparatus). Aliquots (100μL) are taken from the plasma and the buffer compartments, respectively.The matrix effects are eliminated by adding the same volume of blankplasma into the samples from buffer compartments and adding the samevolume of phosphate buffer into the samples from plasma compartments.The samples are extracted by using the regular (3:1) proteinprecipitation extraction procedure (acetonitrile with internalstandard). The supernatants are taken for LC/MS/MS analysis. Thepercentage of plasma-protein binding can be calculated by using thefollowing method:

% Free=[Free Drug/Total Drug]*100=[(Peak Area)_(buffer)/(PeakArea)_(plasma)]*100

% Bound=100−% Free.

From the foregoing description, various modifications and changes in thecompositions and methods provided herein will occur to those skilled inthe art. All such modifications coming within the scope of the appendedclaims are intended to be included therein.

All publications, including but not limited to patents and patentapplications, cited in this specification are herein incorporated byreference as if each individual publication were specifically andindividually indicated to be incorporated by reference herein as thoughfully set forth.

At least some of the chemical names of compounds of the invention asgiven and set forth in this application, may have been generated on anautomated basis by use of a commercially available chemical namingsoftware program, and have not been independently verified.Representative programs performing this function include the Lexichemnaming tool sold by Open Eye Software, Inc. and the Autonom Softwaretool sold by MDL, Inc. In the instance where the indicated chemical nameand the depicted structure differ, the depicted structure will control.

Chemical structures shown herein were prepared using ISIS®/DRAW. Anyopen valency appearing on a carbon, oxygen or nitrogen atom in thestructures herein indicates the presence of a hydrogen atom. Where achiral center exists in a structure but no specific stereochemistry isshown for the chiral center, both enantiomers associated with the chiralstructure are encompassed by the structure.

1. (canceled)
 2. The method according to claim 33, wherein the compound is according to formula 2:

wherein R¹, R² and R⁴ are as in claim 33; and R³ is halo, substituted or unsubstituted C₁-C₆ alkyl or cycloalkyl; or a pharmaceutically acceptable salt, tautomer or isotopic variant thereof.
 3. The method according to claim 33, wherein the compound is an enantiomerically pure compound according to formula 3a or 3b:

wherein R¹, R² and R⁴ are as in claim 33; and R³ is halo, substituted or unsubstituted C₁-C₆ alkyl or cycloalkyl; or a pharmaceutically acceptable salt, solvate, prodrug, tautomer or isotopic variant thereof.
 4. (canceled)
 5. (canceled)
 6. (canceled)
 7. The method according to claim 33, wherein R¹ is selected from unsubstituted phenyl, pyridyl, pyrimidinyl quinolinyl, isoquinolinyl, quinoxaline, methylenedioxyphenyl, imidazopyridyl, benzoxazolyl, and indolyl.
 8. The method according to claim 33, wherein R¹ is selected from quinolinyl, isoquinolinyl, quinoxaline, methylenedioxyphenyl, imidazopyridyl, benzoxazolyl, and indolyl, substituted with one or more groups selected from Me, Et, Pr, iso-Pr, Ph, Cl, F, Br, CN, OH, OMe, OEt, OPh, COPh, CO₂Me, CH₂—N-morpholino, CH₂—N-(4-Me-piperidino), NH₂, CONH₂, CF₃, CHF₂, OCF₃, OCHF₂, t-Bu, SMe, CH═CH—CO₂H, SOMe, SO₂Me, SO₂CF₃, SO₂NH₂, SO₃H, SO₃Me, and cyclopropyl.
 9. The method according to claim 33, wherein R¹ is

and wherein subscript n′ is selected from 1-5 and each R⁵ is independently selected from hydrogen, substituted or unsubstituted alkyl, substituted or unsubstituted acyl, substituted or unsubstituted acylamino, substituted or unsubstituted alkylamino, substituted or unsubstituted alkythio, substituted or unsubstituted alkoxy, aryloxy, alkoxycarbonyl, substituted alkoxycarbonyl, substituted or unsubstituted alkylarylamino, arylalkyloxy, substituted arylalkyloxy, amino, aryl, substituted aryl, arylalkyl, —SO₃H, —SO₃R^(61b), wherein R^(61b) is a substituted or unsubstituted alkyl or a substituted or unsubstituted aryl, —S(O₂)R⁶¹, wherein R⁶¹ is a substituted or unsubstituted alkyl or a substituted or unsubstituted aryl, —SOR^(61a), wherein R^(61a) is a substituted or unsubstituted alkyl, a substituted or unsubstituted aryl or a substituted or unsubstituted heteroaryl, —SR, wherein R is a substituted or unsubstituted alkyl, a substituted or unsubstituted aryl or a substituted or unsubstituted heteroaryl, azido, substituted or unsubstituted carbamoyl, carboxyl, cyano, substituted or unsubstituted cycloalkyl, substituted or unsubstituted cycloheteroalkyl, substituted or unsubstituted dialkylamino, halo, heteroaryloxy, substituted or unsubstituted heteroaryl, substituted or unsubstituted heteroalkyl, hydroxy, nitro, and SH.
 10. (canceled)
 11. (canceled)
 12. The method according to claim 9, wherein the subscript n′ is 1 or 2; and each R⁵ is independently selected from H, Me, Et, Pr, iso-Pr, Ph, Cl, F, Br, CN, OH, OMe, OEt, OPh, COPh, CO₂Me, CH₂—N-morpholino, CH₂—N-(4-Me-piperidino), NH₂, CONH₂, CF₃, CHF₂, OCF₃, OCHF₂, t-Bu, SMe, CH═CH—CO₂H, SOMe, SO₂Me, SO₂CF₃, SO₂NH₂, SO₃H, SO₃Me, cyclopropyl, triazolyl, morpholinyl, and pyridyl.
 13. The method according to claim 33, wherein the compound is according to formula 4a, 4b, or 4c:

and wherein R² is as in claim 33; R³ is halo, substituted or unsubstituted C₁-C₆ alkyl or cycloalkyl; and each R⁵ is independently selected from hydrogen, substituted or unsubstituted alkyl, substituted or unsubstituted acyl, substituted or unsubstituted acylamino, substituted or unsubstituted alkylamino, substituted or unsubstituted alkythio, substituted or unsubstituted alkoxy, aryloxy, alkoxycarbonyl, substituted alkoxycarbonyl, substituted or unsubstituted alkylarylamino, arylalkyloxy, substituted arylalkyloxy, amino, aryl, substituted aryl, arylalkyl, —SO₃H, —SO₃R^(61b), wherein R^(61b) is a substituted or unsubstituted alkyl or a substituted or unsubstituted aryl, —S(O₂)R⁶¹, wherein R⁶¹ is a substituted or unsubstituted alkyl or a substituted or unsubstituted aryl, —SOR^(61a), wherein R^(61a) is a substituted or unsubstituted alkyl, a substituted or unsubstituted aryl or a substituted or unsubstituted heteroaryl, —SR, wherein R is a substituted or unsubstituted alkyl, a substituted or unsubstituted aryl or a substituted or unsubstituted heteroaryl, azido, substituted or unsubstituted carbamoyl, carboxyl, cyano, substituted or unsubstituted cycloalkyl, substituted or unsubstituted cycloheteroalkyl, substituted or unsubstituted dialkylamino, halo, heteroaryloxy, substituted or unsubstituted heteroaryl, substituted or unsubstituted heteroalkyl, hydroxy, nitro, and SH.
 14. The method according to claim 9, wherein each R⁵ is independently selected from H, Me, Et, Pr, iso-Pr, Ph, Cl, F, CN, OH, OMe, OEt, OPh, CF₃, CHF₂, OCF₃, OCHF₂, t-Bu, SO₂Me, SO₂CF₃, and SO₃Me.
 15. A compound according to claim 9, wherein R⁵ is H, Cl, F, Me, CF₃, or OMe.
 16. The method according to claim 33, wherein R² is selected from H, Me, Et, n-Pr, t-Bu, CF₃, CH₂OH, CH₂CH₂OH, CH₂CH₂OAc, CH₂(CH₂)₂OH, CH₂CH₂NHMe, CH₂NMe₂, CH₂CH₂NMe₂, CH₂CONH₂, CH₂CONMe₂, CH₂COOH, CH₂CH₂COOH, CH₂(CH₂)₂COOH, CH₂OMe, and CH₂CH₂OMe.
 17. The method according to claim 33, wherein R² is selected from CH₂NR^(2′)R^(2″), CH₂CH₂NR^(2′)R^(2″), and CH₂CH₂CH₂NR^(2′)R^(2″); and wherein R^(2′) and R^(2″) can join together to form a heterocyclic ring.
 18. The method according to claim 33, wherein R² is selected from cyclopropyl, cyclobutyl or cyclohexyl.
 19. The method according to claim 33, wherein R² is Me.
 20. The method according to claim 33, R² is CH₂OH or CH₂CH₂OH.
 21. The method according to claim 33, wherein R³ is substituted or unsubstituted alkyl.
 22. The method according to claim 33, wherein R³ is Me or CF₃.
 23. (canceled)
 24. The method according to claim 33, R³ is Cl.
 25. The method according to claim 33, wherein the compound is according to formula 5a, 5b, or 5c:

and wherein R² is as in claim 33; and R⁵ is independently selected from hydrogen, substituted or unsubstituted alkyl, substituted or unsubstituted acyl, substituted or unsubstituted acylamino, substituted or unsubstituted alkylamino, substituted or unsubstituted alkythio, substituted or unsubstituted alkoxy, aryloxy, alkoxycarbonyl, substituted alkoxycarbonyl, substituted or unsubstituted alkylarylamino, arylalkyloxy, substituted arylalkyloxy, amino, aryl, substituted aryl, arylalkyl, —SO₃H, —SO₃R^(61b), wherein R^(61b) is a substituted or unsubstituted alkyl or a substituted or unsubstituted aryl, —S(O₂)R⁶¹, wherein R⁶¹ is a substituted or unsubstituted alkyl or a substituted or unsubstituted aryl, —SOR^(61a), wherein R^(61a) is a substituted or unsubstituted alkyl, a substituted or unsubstituted aryl or a substituted or unsubstituted heteroaryl, —SR, wherein R is a substituted or unsubstituted alkyl, a substituted or unsubstituted aryl or a substituted or unsubstituted heteroaryl, azido, substituted or unsubstituted carbamoyl, carboxyl, cyano, substituted or unsubstituted cycloalkyl, substituted or unsubstituted cycloheteroalkyl, substituted or unsubstituted dialkylamino, halo, heteroaryloxy, substituted or unsubstituted heteroaryl, substituted or unsubstituted heteroalkyl, hydroxy, nitro, and SH.
 26. The method according to claim 25, wherein R² is H, Me, Et, CH₂OH, or CH₂CH₂OH.
 27. The method according to claim 25, wherein R⁵ is H, Cl, F, Me, CF₃, or OMe.
 28. The method according to claim 33, selected from the group consisting of: 5-Methyl-2-{4-[(6-trifluoromethyl-pyridin-3-ylmethyl)-amino]-7,8-dihydro-5H-pyrido[4,3-d]pyrimidin-6-yl}-benzonitrile; 5-Bromo-2-{4-[(6-trifluoromethyl-pyridin-3-ylmethyl)-amino]-7,8-dihydro-5H-pyrido[4,3-d]pyrimidin-6-yl}-benzonitrile; 5-Cyclopropyl-2-{4-[(6-trifluoromethyl-pyridin-3-ylmethyl)-amino]-7,8-dihydro-5H-pyrido[4,3-d]pyrimidin-6-yl}-benzonitrile; 5-Chloro-2-{4-[(6-trifluoromethyl-pyridin-3-ylmethyl)-amino]-7,8-dihydro-5H-pyrido[4,3-d]pyrimidin-6-yl}-benzonitrile; 5-Trifluoromethyl-2-{4-[(6-trifluoromethyl-pyridin-3-ylmethyl)-amino]-7,8-dihydro-5H-pyrido[4,3-d]pyrimidin-6-yl}-benzonitrile; 5-Bromo-2-{4-[(R)-1-(6-trifluoromethyl-pyridin-3-yl)-ethylamino]-7,8-dihydro-5H-pyrido[4,3-d]pyrimidin-6-yl}-benzonitrile; 5-Methyl-2-{4-[(R)-1-(6-trifluoromethyl-pyridin-3-yl)-ethylamino]-7,8-dihydro-5H-pyrido[4,3-d]pyrimidin-6-yl}-benzonitrile; 5-Chloro-2-{4-[(R)-1-(6-trifluoromethyl-pyridin-3-yl)-ethylamino]-7,8-dihydro-5H-pyrido[4,3-d]pyrimidin-6-yl}-benzonitrile; 5-Fluoro-2-{4-[(6-trifluoromethyl-pyridin-3-ylmethyl)-amino]-7,8-dihydro-5H-pyrido[4,3-d]pyrimidin-6-yl}-benzonitrile; 2-{4-[(6-Trifluoromethyl-pyridin-3-ylmethyl)-amino]-7,8-dihydro-5H-pyrido[4,3-d]pyrimidin-6-yl}-benzonitrile; 5-Chloro-2-{4-[(2-methyl-6-trifluoromethyl-pyridin-3-ylmethyl)-amino]-7,8-dihydro-5H-pyrido[4,3-d]pyrimidin-6-yl}-benzonitrile; 5-Chloro-2-{4-[(6-dimethylamino-pyridin-3-ylmethyl)-amino]-7,8-dihydro-5H-pyrido[4,3-d]pyrimidin-6-yl}-benzonitrile; 5-Chloro-2-{4-[(6-methoxy-pyridin-3-ylmethyl)-amino]-7,8-dihydro-5H-pyrido[4,3-d]pyrimidin-6-yl}-benzonitrile; 5-Bromo-2-{4-[(6-methoxy-pyridin-3-ylmethyl)-amino]-7,8-dihydro-5H-pyrido[4,3-d]pyrimidin-6-yl}-benzonitrile; 2-{4-[(6-Methoxy-pyridin-3-ylmethyl)-amino]-7,8-dihydro-5H-pyrido[4,3-d]pyrimidin-6-yl}-5-methyl-benzonitrile; 5-Chloro-2-{4-[(3-chloro-5-trifluoromethyl-pyridin-2-ylmethyl)-amino]-7,8-dihydro-5H-pyrido[4,3-d]pyrimidin-6-yl}-benzonitrile; 5-Chloro-2-{4-[(5-trifluoromethyl-pyridin-2-ylmethyl)-amino]-7,8-dihydro-5H-pyrido[4,3-d]pyrimidin-6-yl}-benzonitrile; (R)-3-[6-(4-Chloro-2-cyano-phenyl)-5,6,7,8-tetrahydro-pyrido[4,3-d]pyrimidin-4-ylamino]-3-(6-methoxy-pyridin-3-yl)-propionic acid tert-butyl ester; (R)-3-[6-(4-Chloro-2-cyano-phenyl)-5,6,7,8-tetrahydro-pyrido[4,3-d]pyrimidin-4-ylamino]-3-(6-methoxy-pyridin-3-yl)-propionic acid; 5-Chloro-2-{4-[(R)-3-hydroxy-1-(6-trifluoromethyl-pyridin-3-yl)-propylamino]-7,8-dihydro-5H-pyrido[4,3-d]pyrimidin-6-yl}-benzonitrile; 2-{4-[(R)-3-Hydroxy-1-(6-methyl-pyridin-3-yl)-propylamino]-7,8-dihydro-5H-pyrido[4,3-d]pyrimidin-6-yl}-5-methyl-benzonitrile; 2-{4-[(R)-1-(6-Difluoromethyl-pyridin-3-yl)-3-hydroxy-propylamino]-7,8-dihydro-5H-pyrido[4,3-d]pyrimidin-6-yl}-5-methyl-benzonitrile; 2-{4-[(S)-2-Hydroxy-1-(6-methoxy-pyridin-3-yl)-ethylamino]-7,8-dihydro-5H-pyrido[4,3-d]pyrimidin-6-yl}-5-methyl-benzonitrile; 2-{4-[(R)-3-Hydroxy-1-(6-methoxy-pyridin-3-yl)-propylamino]-7,8-dihydro-5H-pyrido[4,3-d]pyrimidin-6-yl}-5-methyl-benzonitrile; 2-{4-[3-Hydroxy-1-(6-trifluoromethyl-pyridin-3-yl)-propylamino]-7,8-dihydro-5H-pyrido[4,3-d]pyrimidin-6-yl}-5-methyl-benzonitrile; 2-{4-[(S)-2-Methoxy-1-(6-methoxy-pyridin-3-yl)-ethylamino]-7,8-dihydro-5H-pyrido[4,3-d]pyrimidin-6-yl}-5-methyl-benzonitrile; 2-{4-[(6-Chloro-pyridin-3-ylmethyl)-amino]-7,8-dihydro-5H-pyrido[4,3-d]pyrimidin-6-yl}-5-methyl-benzonitrile; 2-{4-[(5-Chloro-pyridin-2-ylmethyl)-amino]-7,8-dihydro-5H-pyrido[4,3-d]pyrimidin-6-yl}-5-methyl-benzonitrile; 5-Methyl-2-{4-[(pyridin-2-ylmethyl)-amino]-7,8-dihydro-5H-pyrido[4,3-d]pyrimidin-6-yl}-benzonitrile; 2-{4-[(5-Cyclopropyl-pyridin-2-ylmethyl)-amino]-7,8-dihydro-5H-pyrido[4,3-d]pyrimidin-6-yl}-5-methyl-benzonitrile; 2-{4-[(4-Amino-2-methyl-pyrimidin-5-ylmethyl)-amino]-7,8-dihydro-5H-pyrido[4,3-d]pyrimidin-6-yl}-5-methyl-benzonitrile; 2-{4-[(3,5-Dichloro-pyridin-2-ylmethyl)-amino]-7,8-dihydro-5H-pyrido[4,3-d]pyrimidin-6-yl}-5-methyl-benzonitrile; 2-{4-[(6-Ethyl-pyridin-3-ylmethyl)-amino]-7,8-dihydro-5H-pyrido[4,3-d]pyrimidin-6-yl}-5-methyl-benzonitrile; 5-Chloro-2-{4-[(R)-3-hydroxy-1-(6-methoxy-pyridin-3-yl)-propylamino]-7,8-dihydro-5H-pyrido[4,3-d]pyrimidin-6-yl}-benzonitrile; 5-Chloro-2-{4-[(S)-2-hydroxy-1-(6-methoxy-pyridin-3-yl)-ethylamino]-7,8-dihydro-5H-pyrido[4,3-d]pyrimidin-6-yl}-benzonitrile; 2-[4-(3-Cyano-benzylamino)-7,8-dihydro-5H-pyrido[4,3-d]pyrimidin-6-yl]-5-methyl-benzonitrile; 2-{4-[(Imidazo[1,2-a]pyridin-7-ylmethyl)-amino]-7,8-dihydro-5H-pyrido[4,3-d]pyrimidin-6-yl}-5-methyl-benzonitrile; 2-{4-[(Benzooxazol-5-ylmethyl)-amino]-7,8-dihydro-5H-pyrido[4,3-d]pyrimidin-6-yl}-5-methyl-benzonitrile; 5-Methyl-2-{4-[(2-methyl-pyrimidin-5-ylmethyl)-amino]-7,8-dihydro-5H-pyrido[4,3-d]pyrimidin-6-yl}-benzonitrile; 5-Methyl-2-[4-(4-methyl-3-[1,2,4]triazol-1-yl-benzylamino)-7,8-dihydro-5H-pyrido[4,3-d]pyrimidin-6-yl]-benzonitrile; (R)-3-[6-(2-Cyano-4-methyl-phenyl)-5,6,7,8-tetrahydro-pyrido[4,3-d]pyrimidin-4-ylamino]-3-(6-methoxy-pyridin-3-yl)-propionic acid; (R)-3-[6-(2-Cyano-4-methyl-phenyl)-5,6,7,8-tetrahydro-pyrido[4,3-d]pyrimidin-4-ylamino]-3-(6-methoxy-pyridin-3-yl)-propionamide; (R)-3-[6-(2-Cyano-4-methyl-phenyl)-5,6,7,8-tetrahydro-pyrido[4,3-d]pyrimidin-4-ylamino]-3-(6-methoxy-pyridin-3-yl)-N,N-dimethyl-propionamide; 5-Chloro-2-{4-[(imidazo[1,2-a]pyridin-7-ylmethyl)-amino]-7,8-dihydro-5H-pyrido[4,3-d]pyrimidin-6-yl}-benzonitrile; 5-Chloro-2-{4-[(2-methyl-pyrimidin-5-ylmethyl)-amino]-7,8-dihydro-5H-pyrido[4,3-d]pyrimidin-6-yl}-benzonitrile; 2-{4-[(S)-2-Hydroxy-1-(6-trifluoromethyl-pyridin-3-yl)-ethylamino]-7,8-dihydro-5H-pyrido[4,3-d]pyrimidin-6-yl}-5-methyl-benzonitrile; 5-Chloro-2-{4-[(S)-2-hydroxy-1-(6-trifluoromethyl-pyridin-3-yl)-ethylamino]-7,8-dihydro-5H-pyrido[4,3-d]pyrimidin-6-yl}-benzonitrile; 2-[4-(3-Fluoro-4-methyl-benzylamino)-7,8-dihydro-5H-pyrido[4,3-d]pyrimidin-6-yl]-5-methyl-benzonitrile; 5-Methyl-2-[4-(4-methyl-3-methylsulfanyl-benzylamino)-7,8-dihydro-5H-pyrido[4,3-d]pyrimidin-6-yl]-benzonitrile; 2-[4-(4-Chloro-3-[1,2,4]triazol-4-yl-benzylamino)-7,8-dihydro-5H-pyrido[4,3-d]pyrimidin-6-yl]-5-methyl-benzonitrile; 5-Chloro-2-[4-(3-[1,2,4]triazol-4-yl-benzylamino)-7,8-dihydro-5H-pyrido[4,3-d]pyrimidin-6-yl]-benzonitrile; 5-Chloro-2-[4-(4-chloro-3-[1,2,4]triazol-4-yl-benzylamino)-7,8-dihydro-5H-pyrido[4,3-d]pyrimidin-6-yl]-benzonitrile; 5-Methyl-2-[4-(3-[1,2,4]triazol-4-yl-benzylamino)-7,8-dihydro-5H-pyrido[4,3-d]pyrimidin-6-yl]-benzonitrile; 2-{4-[(4-Amino-2-methoxy-pyrimidin-5-ylmethyl)-amino]-7,8-dihydro-5H-pyrido[4,3-d]pyrimidin-6-yl}-5-methyl-benzonitrile; 2-[4-(3-Iodo-4-methyl-benzylamino)-7,8-dihydro-5H-pyrido[4,3-d]pyrimidin-6-yl]-5-methyl-benzonitrile; 5-Chloro-2-{4-[(R)-1-(2-methoxy-pyrimidin-5-yl)-ethylamino]-7,8-dihydro-5H-pyrido[4,3-d]pyrimidin-6-yl}-benzonitrile; 2-{4-[(R)-1-(2-Methoxy-pyrimidin-5-yl)-ethylamino]-7,8-dihydro-5H-pyrido[4,3-d]pyrimidin-6-yl}-5-methyl-benzonitrile; 2-[4-(3-Methanesulfonyl-4-methyl-benzylamino)-7,8-dihydro-5H-pyrido[4,3-d]pyrimidin-6-yl]-5-methyl-benzonitrile; 2-{4-[(S)-2-Hydroxy-1-(2-methoxy-pyrimidin-5-yl)-ethylamino]-7,8-dihydro-5H-pyrido[4,3-d]pyrimidin-6-yl}-5-methyl-benzonitrile; 2-{4-[(2-Isopropyl-pyrimidin-5-ylmethyl)-amino]-7,8-dihydro-5H-pyrido[4,3-d]pyrimidin-6-yl}-5-methyl-benzonitrile; 5-Chloro-2-{4-[(R)-1-(6-difluoromethyl-pyridin-3-yl)-3-hydroxy-propylamino]-7,8-dihydro-5H-pyrido[4,3-d]pyrimidin-6-yl}-benzonitrile; 5-Methyl-2-[4-(4-methyl-3-morpholin-4-yl-benzylamino)-7,8-dihydro-5H-pyrido[4,3-d]pyrimidin-6-yl]-benzonitrile; 2-{4-[(R)-3-Hydroxy-1-(6-trifluoromethyl-pyridin-3-yl)-propylamino]-7,8-dihydro-5H-pyrido[4,3-d]pyrimidin-6-yl}-5-methyl-benzonitrile; 2-{4-[(S)-3-Hydroxy-1-(6-trifluoromethyl-pyridin-3-yl)-propylamino]-7,8-dihydro-5H-pyrido[4,3-d]pyrimidin-6-yl}-5-methyl-benzonitrile; 5-Methyl-2-{4-[(R)-1-(2-methyl-pyrimidin-5-yl)-ethylamino]-7,8-dihydro-5H-pyrido[4,3-d]pyrimidin-6-yl}-benzonitrile; 5-Methyl-2-{4-[(S)-1-(2-methyl-pyrimidin-5-yl)-ethylamino]-7,8-dihydro-5H-pyrido[4,3-d]pyrimidin-6-yl}-benzonitrile; 2-{4-[(2-Methoxy-pyrimidin-5-ylmethyl)-amino]-7,8-dihydro-5H-pyrido[4,3-d]pyrimidin-6-yl}-5-methyl-benzonitrile; 5-Chloro-2-{4-[(2-methoxy-pyrimidin-5-ylmethyl)-amino]-7,8-dihydro-5H-pyrido[4,3-d]pyrimidin-6-yl}-benzonitrile; 2-{4-[(S)-1-(6-Difluoromethyl-pyridin-3-yl)-2-hydroxy-ethylamino]-7,8-dihydro-5H-pyrido[4,3-d]pyrimidin-6-yl}-5-methyl-benzonitrile; 2-[4-(4-Chloro-3-methanesulfonyl-benzylamino)-7,8-dihydro-5H-pyrido[4,3-d]pyrimidin-6-yl]-5-methyl-benzonitrile; 5-Chloro-2-{4-[(S)-1-(6-difluoromethyl-pyridin-3-yl)-2-hydroxy-ethylamino]-7,8-dihydro-5H-pyrido[4,3-d]pyrimidin-6-yl}-benzonitrile; 5-Chloro-2-{4-[(S)-2-hydroxy-1-(2-methyl-pyrimidin-5-yl)-ethylamino]-7,8-dihydro-5H-pyrido[4,3-d]pyrimidin-6-yl}-benzonitrile; 2-{4-[(S)-2-Hydroxy-1-(2-methyl-pyrimidin-5-yl)-ethylamino]-7,8-dihydro-5H-pyrido[4,3-d]pyrimidin-6-yl}-5-methyl-benzonitrile; 5-Chloro-2-{4-[(R)-1-(2-methyl-pyrimidin-5-yl)-ethylamino]-7,8-dihydro-5H-pyrido[4,3-d]pyrimidin-6-yl}-benzonitrile; 5-Chloro-2-[4-(3-methanesulfonyl-4-methyl-benzylamino)-7,8-dihydro-5H-pyrido[4,3-d]pyrimidin-6-yl]-benzonitrile; Acetic acid (R)-3-[6-(2-cyano-4-methyl-phenyl)-5,6,7,8-tetrahydro-pyrido[4,3-d]pyrimidin-4-ylamino]-3-(6-trifluoromethyl-pyridin-3-yl)-propyl ester; 5-Chloro-2-{4-[(S)-2-hydroxy-1-(2-methoxy-pyrimidin-5-yl)-ethylamino]-7,8-dihydro-5H-pyrido[4,3-d]pyrimidin-6-yl}-benzonitrile; 5-Methyl-2-{4-[(quinoxalin-6-ylmethyl)-amino]-7,8-dihydro-5H-pyrido[4,3-d]pyrimidin-6-yl}-benzonitrile; 5-Methyl-2-{4-[(quinolin-2-ylmethyl)-amino]-7,8-dihydro-5H-pyrido[4,3-d]pyrimidin-6-yl}-benzonitrile; 2-{4-[(1H-Indol-6-ylmethyl)-amino]-7,8-dihydro-5H-pyrido[4,3-d]pyrimidin-6-yl}-5-methyl-benzonitrile; 2-{4-[(Benzo[1,3]dioxol-5-ylmethyl)-amino]-7,8-dihydro-5H-pyrido[4,3-d]pyrimidin-6-yl}-5-methyl-benzonitrile; 2-[4-(1-Benzo[1,3]dioxol-5-yl-ethylamino)-7,8-dihydro-5H-pyrido[4,3-d]pyrimidin-6-yl]-5-methyl-benzonitrile; 5-Chloro-2-{4-[(quinoxalin-6-ylmethyl)-amino]-7,8-dihydro-5H-pyrido[4,3-d]pyrimidin-6-yl}-benzonitrile; 5-Methyl-2-[4-(1-pyrazin-2-yl-ethylamino)-7,8-dihydro-5H-pyrido[4,3-d]pyrimidin-6-yl]-benzonitrile; 5-Methyl-2-[4-(1-quinoxalin-6-yl-ethylamino)-7,8-dihydro-5H-pyrido[4,3-d]pyrimidin-6-yl]-benzonitrile; 2-{4-[(S)-1-(2-Methoxy-pyrimidin-5-yl)-ethylamino]-7,8-dihydro-5H-pyrido[4,3-d]pyrimidin-6-yl}-5-methyl-benzonitrile; 2-{4-[1-(4-Chloro-3-methanesulfonyl-phenyl)-ethylamino]-7,8-dihydro-5H-pyrido[4,3-d]pyrimidin-6-yl}-5-methyl-benzonitrile; 2-[4-((R)-1-Benzo[1,3]dioxol-5-yl-ethylamino)-7,8-dihydro-5H-pyrido[4,3-d]pyrimidin-6-yl]-5-methyl-benzonitrile; 2-[4-((S)-1-Benzo[1,3]dioxol-5-yl-ethylamino)-7,8-dihydro-5H-pyrido[4,3-d]pyrimidin-6-yl]-5-methyl-benzonitrile; 2-{4-[1-(3-Methanesulfonyl-4-methyl-phenyl)-ethylamino]-7,8-dihydro-5H-pyrido[4,3-d]pyrimidin-6-yl}-5-methyl-benzonitrile; 5-Methyl-2-{4-[(quinolin-7-ylmethyl)-amino]-7,8-dihydro-5H-pyrido[4,3-d]pyrimidin-6-yl}-benzonitrile; 2-{4-[(R)-1-(4-Chloro-3-methanesulfonyl-phenyl)-ethylamino]-7,8-dihydro-5H-pyrido[4,3-d]pyrimidin-6-yl}-5-methyl-benzonitrile; 2-{4-[(S)-1-(4-Chloro-3-methanesulfonyl-phenyl)-ethylamino]-7,8-dihydro-5H-pyrido[4,3-d]pyrimidin-6-yl}-5-methyl-benzonitrile; 5-Methyl-2-[4-((R)-1-quinoxalin-6-yl-ethylamino)-7,8-dihydro-5H-pyrido[4,3-d]pyrimidin-6-yl]-benzonitrile; and 5-Methyl-2-[4-((S)-1-quinoxalin-6-yl-ethylamino)-7,8-dihydro-5H-pyrido[4,3-d]pyrimidin-6-yl]-benzonitrile; 2-[4-(3-cyano-4-methylbenzylamino)-7,8-dihydro-5H-pyrido[4,3-d]pyrimidin-6-yl]-5-methyl-benzonitrile; or a pharmaceutically acceptable salt, solvate, prodrug, stereoisomer, tautomer or isotopic variant thereof.
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 33. A method for preventing or treating in a mammal in need thereof a disease or condition which comprises administering to the mammal an effective disease-treating or condition-treating amount of a pharmaceutical composition, said pharmaceutical composition comprising a pharmaceutically acceptable carrier and a pharmaceutically effective amount of a compound according to formula 1:

wherein R¹ is aryl or heteroaryl unsubstituted or substituted with one or more R⁴ groups; R² is H, substituted or unsubstituted C₁-C₆ alkyl or cycloalkyl; each R³ and R⁴ is independently selected from the group consisting of H, alkyl, acyl, acylamino, alkylamino, alkylthio, alkoxy, alkoxycarbonyl, alkylarylamino, arylalkyloxy, arylalkyloxy, amino, aryl, —SO₃H, —SO₃R^(61b), wherein R^(61b) is a substituted or unsubstituted alkyl or a substituted or unsubstituted aryl, —S(O₂)R⁶¹, wherein R⁶¹ is a substituted or unsubstituted alkyl or a substituted or unsubstituted aryl, —SOR^(61a), wherein R^(61a) is a substituted or unsubstituted alkyl, a substituted or unsubstituted aryl or a substituted or unsubstituted heteroaryl, —SR, wherein R is a substituted or unsubstituted alkyl, a substituted or unsubstituted aryl or a substituted or unsubstituted heteroaryl, azido, carbamoyl, carboxyl, cyano, cycloalkyl, cycloheteroalkyl, dialkylamino, halo, heteroaryloxy, heteroaryl, heteroalkyl, hydroxy, nitro, and SH; and m is 1, 2, 3, or 4; or a pharmaceutically acceptable salt, tautomer or isotopic variant thereof.
 34. The method of claim 33, wherein the disease or condition is selected from: pain including acute, inflammatory and neuropathic pain, chronic pain, dental pain and headache including migraine, cluster headache and tension headache, Parkinson's disease, Alzheimer's disease and multiple sclerosis; diseases and disorders which are mediated by or result in neuroinflammation, encephalitis; centrally-mediated neuropsychiatric diseases and disorders, depression mania, bipolar disease, anxiety, schizophrenia, eating disorders, sleep disorders and cognition disorders; neurological and neurodegenerative diseases and disorders; epilepsy and seizure disorders; prostate, bladder and bowel dysfunction, urinary incontinence, urinary hesitancy, rectal hypersensitivity, fecal incontinence, benign prostatic hypertrophy and inflammatory bowel disease; respiratory and airway disease and disorders, allergic rhinitis, asthma and reactive airway disease and chronic obstructive pulmonary disease; diseases and disorders which are mediated by or result in inflammation, arthritis, rheumatoid arthritis and osteoarthritis, myocardial infarction, autoimmune diseases and disorders, itch/pruritus, psoriasis; obesity; lipid disorders; cancer; and renal disorders.
 35. The method of claim 34, wherein the disease or condition is Parkinson's disease.
 36. The method of claim 34, wherein the disease or condition is Alzheimer's disease.
 37. The method of claim 34, wherein the disease or condition is pain.
 38. The method of claim 37, wherein the pain is associated with a condition selected from the group consisting of postmastectomy pain syndrome, stump pain, phantom limb pain, oral neuropathic pain, Charcot's pain, toothache, venomous snake bite, spider bite, insect sting, postherpetic neuralgia, diabetic neuropathy, reflex sympathetic dystrophy, trigeminal neuralgia, osteoarthritis, rheumatoid arthritis, fibromyalgis, Guillain-Barre syndrome, meralgia paresthetica, burning-mouth syndrome, bilateral peripheral neuropathy, causalgia, sciatic neuritis, peripheral neuritis, polyneuritis, segmental neuritis, Gombault's neuritis, neuronitis, cervicobrachial neuralgia, cranial neuralgia, egniculate neuralgia, glossopharyngial neuralgia, migranous neuralgia, idiopathic neuralgia, intercostals neuralgia, mammary neuralgia, mandibular joint neuralgia, Morton's neuralgia, nasociliary neuralgia, occipital neuralgia, red neuralgia, Sluder's neuralgia splenopalatine neuralgia, supraorbital neuralgia, vidian neuralgia, sinus headache, tension headache, labor, childbirth, intestinal gas, menstruation, cancer, and trauma.
 39. The method of claim 38, wherein the disease or condition is neuropathic pain.
 40. The method of claim 38, wherein the disease or condition is an autoimmune disease.
 41. The method of claim 38, wherein the disease or condition is an inflammatory disease or condition.
 42. The method of claim 38, wherein the disease or condition is a neurological or neurodegenerative disease or condition.
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